The USB standard specifies relatively loose tolerances for compliant USB connectors to minimize physical incompatibilities in connectors from different vendors. To address a weakness present in some other connector standards, the USB specification also defines limits to the size of a connecting device in the area around its plug. This was done to prevent a device from blocking adjacent ports due to the size of the cable strain relief mechanism (usually molding integral with the cable outer insulation) at the connector. Compliant devices must either fit within the size restrictions or support a compliant extension cable that does.

What type of tolerances does the USB standard specify for compliant USB connectors?

loose tolerances

Why were loose tolerances allowed for compliant USB connectors?

to minimize physical incompatibilities in connectors from different vendors

How is a weakness addressed in some other connector standards?

the USB specification also defines limits to the size of a connecting device

Due to size restrictions compliant devices must what?

fit within the size restrictions or support a compliant extension cable that does


In general, USB cables have only plugs on their ends, while hosts and devices have only receptacles. Hosts almost universally have Type-A receptacles, while devices have one or another Type-B variety. Type-A plugs mate only with Type-A receptacles, and the same applies to their Type-B counterparts; they are deliberately physically incompatible. However, an extension to the USB standard specification called USB On-The-Go (OTG) allows a single port to act as either a host or a device, which is selectable by the end of the cable that plugs into the receptacle on the OTG-enabled unit. Even after the cable is hooked up and the units are communicating, the two units may "swap" ends under program control. This capability is meant for units such as PDAs in which the USB link might connect to a PC's host port as a device in one instance, yet connect as a host itself to a keyboard and mouse device in another instance.

USB cables and device have only what on their ends?

plugs

Hosts and devices only have what in terms of connecting to a USB device?

receptacles

Devices usually have what type of receptacle?

one or another Type-B variety

Hosts almost always have what type of receptacle?

Type-A receptacles


Various connectors have been used for smaller devices such as digital cameras, smartphones, and tablet computers. These include the now-deprecated (i.e. de-certified but standardized) mini-A and mini-AB connectors; mini-B connectors are still supported, but are not OTG-compliant (On The Go, used in mobile devices). The mini-B USB connector was standard for transferring data to and from the early smartphones and PDAs. Both mini-A and mini-B plugs are approximately 3 by 7 mm; the mini-A connector and the mini-AB receptacle connector were deprecated on 23 May 2007.

What has been used to connect digital cameras. smartphones and other devices to tablet computers?

Various connectors

What was standard for transferring data to and from the earlier type of smartphones?

The mini-B USB connector

How large are both mini-A and mini-B plugs?

approximately 3 by 7 mm

When were the mini-A connector and and the mini-AB receptacle connector depreceated?

23 May 2007


The micro plug design is rated for at least 10,000 connect-disconnect cycles, which is more than the mini plug design. The micro connector is also designed to reduce the mechanical wear on the device; instead the easier-to-replace cable is designed to bear the mechanical wear of connection and disconnection. The Universal Serial Bus Micro-USB Cables and Connectors Specification details the mechanical characteristics of micro-A plugs, micro-AB receptacles (which accept both micro-A and micro-B plugs), and micro-B plugs and receptacles, along with a standard-A receptacle to micro-A plug adapter.

What is the micro connector designed for?

to reduce the mechanical wear on the device

What is the easier-to-replace cable designed for?

to bear the mechanical wear of connection and disconnection

What is the micro-plug rated for?

10,000 connect-disconnect cycles


The cellular phone carrier group Open Mobile Terminal Platform (OMTP) in 2007 endorsed micro-USB as the standard connector for data and power on mobile devices In addition, on 22 October 2009 the International Telecommunication Union (ITU) has also announced that it had embraced micro-USB as the Universal Charging Solution its "energy-efficient one-charger-fits-all new mobile phone solution," and added: "Based on the Micro-USB interface, UCS chargers also include a 4-star or higher efficiency rating—up to three times more energy-efficient than an unrated charger."

In 2007 who endorsed micro-USB as the standard connector for data and power on mobile devices?

The cellular phone carrier group Open Mobile Terminal Platform

When did the ITU announce that it had embraced micro-USB as the Universal Charging Solution?

22 October 2009

What has energy-efficient one-charger-fits-all new mobile phone solution?

micro-USB


The European Standardisation Bodies CEN, CENELEC and ETSI (independent of the OMTP/GSMA proposal) defined a common External Power Supply (EPS) for use with smartphones sold in the EU based on micro-USB. 14 of the world's largest mobile phone manufacturers signed the EU's common EPS Memorandum of Understanding (MoU). Apple, one of the original MoU signers, makes micro-USB adapters available – as permitted in the Common EPS MoU – for its iPhones equipped with Apple's proprietary 30-pin dock connector or (later) Lightning connector.

Who defined a common External Power Supply for use with smartphones sold?

The European Standardisation Bodies CEN, CENELEC and ETSI

How many mobile phone manufacturers signed the EU's common EPS (MoU)?

Who was one of the original MoU signers?

Apple


All current USB On-The-Go (OTG) devices are required to have one, and only one, USB connector: a micro-AB receptacle. Non-OTG compliant devices are not allowed to use the micro-AB receptacle, due to power supply shorting hazards on the VBUS line. The micro-AB receptacle is capable of accepting both micro-A and micro-B plugs, attached to any of the legal cables and adapters as defined in revision 1.01 of the micro-USB specification. Prior to the development of micro-USB, USB On-The-Go devices were required to use mini-AB receptacles to perform the equivalent job.

What are all USB On-The-Go devices required to have?

one, and only one, USB connector

Non-OTG compliant devices are not allowed to use what?

the micro-AB receptacle

Why are the Non-OTG compliant devices not allowed to use the micro-AB receptacle?

power supply shorting hazards on the VBUS line


The OTG device with the A-plug inserted is called the A-device and is responsible for powering the USB interface when required and by default assumes the role of host. The OTG device with the B-plug inserted is called the B-device and by default assumes the role of peripheral. An OTG device with no plug inserted defaults to acting as a B-device. If an application on the B-device requires the role of host, then the Host Negotiation Protocol (HNP) is used to temporarily transfer the host role to the B-device.

The OTG device with the B-plug inserted is called what?

B-device

What does an OTG device default to with no plug inserted?

to acting as a B-device

What is the A-device responsible for?

powering the USB interface when required


USB is a serial bus, using four shielded wires for the USB 2.0 variant: two for power (VBUS and GND), and two for differential data signals (labelled as D+ and D− in pinouts). Non-Return-to-Zero Inverted (NRZI) encoding scheme is used for transferring data, with a sync field to synchronize the host and receiver clocks. D+ and D− signals are transmitted on a twisted pair, providing half-duplex data transfers for USB 2.0. Mini and micro connectors have their GND connections moved from pin #4 to pin #5, while their pin #4 serves as an ID pin for the On-The-Go host/client identification.

What is USB?

a serial bus

What kind of wires does the USB 2.0 variant use?

four shielded wires

What are the four shielded wires in the USB 2.0 variant used for?

two for power (VBUS and GND), and two for differential data signals


USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed (480 Mbit/s). The primary reason for this limit is the maximum allowed round-trip delay of about 1.5 μs. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to 26 ns. The USB 2.0 specification requires that cable delay be less than 5.2 ns per meter (192 000 km/s, which is close to the maximum achievable transmission speed for standard copper wire).

How long is the maximum cable length the USB 2.0 provides?

5 meters for devices running at Hi Speed

What is the maximum acceptable delay per cable?

26 ns

What does theUSB 2.0 specification require?

cable delay be less than 5.2 ns per meter


A unit load is defined as 100 mA in USB 1.x and 2.0, and 150 mA in USB 3.0. A device may draw a maximum of five unit loads from a port in USB 1.x and 2.0 (500 mA), or six unit loads in USB 3.0 (900 mA). There are two types of devices: low-power and high-power. A low-power device (such as a USB HID) draws at most one-unit load, with minimum operating voltage of 4.4 V in USB 2.0, and 4 V in USB 3.0. A high-power device draws, at most, the maximum number of unit loads the standard permits. Every device functions initially as low-power (including high-power functions during their low-power enumeration phases), but may request high-power, and get it if available on the providing bus.

What is a unit load defined as?

100 mA in USB 1.x and 2.0

How much is a unit load in USB 3.0?

150 mA

What is the maximum amount of load a USB 1. and 2.0 device may draw?

five unit loads

What is the maximum amount of load a USB 3.0 device may draw?

six unit loads


Some devices, such as high-speed external disk drives, require more than 500 mA of current and therefore may have power issues if powered from just one USB 2.0 port: erratic function, failure to function, or overloading/damaging the port. Such devices may come with an external power source or a Y-shaped cable that has two USB connectors (one for power and data, the other for power only) to plug into a computer. With such a cable, a device can draw power from two USB ports simultaneously. However, USB compliance specification states that "use of a 'Y' cable (a cable with two A-plugs) is prohibited on any USB peripheral", meaning that "if a USB peripheral requires more power than allowed by the USB specification to which it is designed, then it must be self-powered."

What is an example of a device that requires more than 500 mA of current?

high-speed external disk drives

What is an issue that may occur if a high-speed external disk drive is powered from just one USB 2.0 port.

may have power issues

What does USB compliance specification prohibit?

"use of a 'Y' cable (a cable with two A-plugs)


The USB Battery Charging Specification Revision 1.1 (released in 2007) defines a new type of USB port, called the charging port. Contrary to the standard downstream port, for which current draw by a connected portable device can exceed 100 mA only after digital negotiation with the host or hub, a charging port can supply currents between 500 mA and 1.5 A without the digital negotiation. A charging port supplies up to 500 mA at 5 V, up to the rated current at 3.6 V or more, and drops its output voltage if the portable device attempts to draw more than the rated current. The charger port may shut down if the load is too high.

What defines a new type of USB port, called the charging port?

The USB Battery Charging Specification Revision 1.1

When was the USB Battery Charging Specification Revision 1.1 released?

in 2007

What was the USB Battery Charging Specification Revision 1.1 called?

the charging port

What does a charging port supply?

up to 500 mA at 5 V


Two types of charging port exist: the charging downstream port (CDP), supporting data transfers as well, and the dedicated charging port (DCP), without data support. A portable device can recognize the type of USB port; on a dedicated charging port, the D+ and D− pins are shorted with a resistance not exceeding 200 ohms, while charging downstream ports provide additional detection logic so their presence can be determined by attached devices. (see ref pg. 2, Section 1.4.5, & Table 5-3 "Resistances"—pg. 29).

How many types of charging ports exist?

Two types

What can a portable device recognize?

the type of USB port

What are the D+ and D- shortened with?

a resistance not exceeding 200 ohms


The USB Battery Charging Specification Revision 1.2 (released in 2010) makes clear that there are safety limits to the rated current at 5 A coming from USB 2.0. On the other hand, several changes are made and limits are increasing including allowing 1.5 A on charging downstream ports for unconfigured devices, allowing high speed communication while having a current up to 1.5 A, and allowing a maximum current of 5 A. Also, revision 1.2 removes support for USB ports type detection via resistive detection mechanisms.

What does the USB Battery Charging Specification Revision 1.2 make clear of?

there are safety limits to the rated current at 5 A coming from USB 2.0

What does revision 1.2 remove?

USB ports type detection via resistive detection mechanisms

When was USB Battery Charging Specification Revision 1.2 released?

in 2010


In July 2012, the USB Promoters Group announced the finalization of the USB Power Delivery ("PD") specification, an extension that specifies using certified "PD aware" USB cables with standard USB Type-A and Type-B connectors to deliver increased power (more than 7.5 W) to devices with larger power demand. Devices can request higher currents and supply voltages from compliant hosts –  up to 2 A at 5 V (for a power consumption of up to 10 W), and optionally up to 3 A or 5 A at either 12 V (36 W or 60 W) or 20 V (60 W or 100 W). In all cases, both host-to-device and device-to-host configurations are supported.

When did the USB Promoters Group announce the finalization of the USB Power Delivery specification?

In July 2012

What can devices request?

higher currents and supply voltages from compliant hosts

In all cases, both host-to-device and device-to-host configurations are what?

supported


The USB Power Delivery revision 2.0 specification has been released as part of the USB 3.1 suite. It covers the Type-C cable and connector with four power/ground pairs and a separate configuration channel, which now hosts a DC coupled low-frequency BMC-coded data channel that reduces the possibilities for RF interference. Power Delivery protocols have been updated to facilitate Type-C features such as cable ID function, Alternate Mode negotiation, increased VBUS currents, and VCONN-powered accessories.

The USB Power Delivery revision 2.0 specification has been released as part of what?

USB 3.1

What does the USB Power Delivery revision 2.0 specification cover?

Type-C cable and connector with four power/ground pairs and a separate configuration channel

Power delivery protocols have been updated to facilitate what?

Type-C features


Sleep-and-charge USB ports can be used to charge electronic devices even when the computer is switched off. Normally, when a computer is powered off the USB ports are powered down, preventing phones and other devices from charging. Sleep-and-charge USB ports remain powered even when the computer is off. On laptops, charging devices from the USB port when it is not being powered from AC drains the laptop battery faster; most laptops have a facility to stop charging if their own battery charge level gets too low.

What can sleep-and-charge USB ports be used to do?

charge electronic devices even when the computer is switched off

What is normally powered off whenever the computer is off?

USB ports

What remain powered even whenever the computer is powered off?

Sleep-and-charge USB ports


On Dell and Toshiba laptops, the port is marked with the standard USB symbol with an added lightning bolt icon on the right side. Dell calls this feature PowerShare, while Toshiba calls it USB Sleep-and-Charge. On Acer Inc. and Packard Bell laptops, sleep-and-charge USB ports are marked with a non-standard symbol (the letters USB over a drawing of a battery); the feature is simply called Power-off USB. On some laptops such as Dell and Apple MacBook models, it is possible to plug a device in, close the laptop (putting it into sleep mode) and have the device continue to charge.[citation needed]

On what laptops are the USB ports marked with a USB symbol with an added lightening bolt icon?

On Dell and Toshiba laptops

What does dell call the feature that lets USB drives to remain powered when the computer is off?

PowerShare

On what laptops are the sleep-and-charge marked with a non-standard symbol?

On Acer Inc. and Packard Bell laptops


The GSM Association (GSMA) followed suit on 17 February 2009, and on 22 April 2009, this was further endorsed by the CTIA – The Wireless Association, with the International Telecommunication Union (ITU) announcing on 22 October 2009 that it had also embraced the Universal Charging Solution as its "energy-efficient one-charger-fits-all new mobile phone solution," and added: "Based on the Micro-USB interface, UCS chargers will also include a 4-star or higher efficiency rating—up to three times more energy-efficient than an unrated charger."

When did the GSM Association follow suit?

17 February 2009

When was this further endorsed by the CTIA?

22 April 2009

UCS chargers will also include what?

a 4-star or higher efficiency rating


In June 2009, many of the world's largest mobile phone manufacturers signed an EC-sponsored Memorandum of Understanding (MoU), agreeing to make most data-enabled mobile phones marketed in the European Union compatible with a common External Power Supply (EPS). The EU's common EPS specification (EN 62684:2010) references the USB Battery Charging standard and is similar to the GSMA/OMTP and Chinese charging solutions. In January 2011, the International Electrotechnical Commission (IEC) released its version of the (EU's) common EPS standard as IEC 62684:2011.

When did many of the largest mobile phone manufacturers sign an EC-sponsored MoU?

June 2009

What did the MoU make the manufacturers agree to do?

to make most data-enabled mobile phones marketed in the European Union compatible with a common External Power Supply

When did the IEC release its version of the common EPS standard as IEC 62684:2011?

January 2011


Some USB devices require more power than is permitted by the specifications for a single port. This is common for external hard and optical disc drives, and generally for devices with motors or lamps. Such devices can use an external power supply, which is allowed by the standard, or use a dual-input USB cable, one input of which is used for power and data transfer, the other solely for power, which makes the device a non-standard USB device. Some USB ports and external hubs can, in practice, supply more power to USB devices than required by the specification but a standard-compliant device may not depend on this.

Some USB devices require what?

more power than is permitted by the specifications for a single port.

Some devices such as an external hard and optical disk drive can use what?

an external power supply

What is another alternative for power for an external hard and optical disk drive?

a dual-input USB cable

What is the purpose of a dual-input USB cable?

one input of which is used for power and data transfer, the other solely for power


In addition to limiting the total average power used by the device, the USB specification limits the inrush current (i.e., that used to charge decoupling and filter capacitors) when the device is first connected. Otherwise, connecting a device could cause problems with the host's internal power. USB devices are also required to automatically enter ultra low-power suspend mode when the USB host is suspended. Nevertheless, many USB host interfaces do not cut off the power supply to USB devices when they are suspended.

What does the USB specification limit?

the inrush current

When is the inrush current affected by the USB specification?

when the device is first connected

What are USB devices required to enter?

ultra low-power suspend mode when the USB host is suspended

Many USB host interfaces do not what?

cut off the power supply to USB devices when they are suspended


Some non-standard USB devices use the 5 V power supply without participating in a proper USB network, which negotiates power draw with the host interface. These are usually called USB decorations.[citation needed] Examples include USB-powered keyboard lights, fans, mug coolers and heaters, battery chargers, miniature vacuum cleaners, and even miniature lava lamps. In most cases, these items contain no digital circuitry, and thus are not standard compliant USB devices. This may cause problems with some computers, such as drawing too much current and damaging circuitry. Prior to the Battery Charging Specification, the USB specification required that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host, which then permits the device to switch into high-power mode.

What do some non-standard USB devices use?

the 5 V power supply without participating in a proper USB network

What Negotiates power draw with the host interface?

the 5 V power supply

What does the USB specification require prior to the Battery Charging Specification?

that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host


USB data is transmitted by toggling the data lines between the J state and the opposite K state. USB encodes data using the NRZI line coding; a 0 bit is transmitted by toggling the data lines from J to K or vice versa, while a 1 bit is transmitted by leaving the data lines as-is. To ensure a minimum density of signal transitions remains in the bitstream, USB uses bit stuffing; an extra 0 bit is inserted into the data stream after any appearance of six consecutive 1 bits. Seven consecutive received 1 bits is always an error. USB 3.0 has introduced additional data transmission encodings.

How is the USB data transmitted?

by toggling the data lines between the J state and the opposite K state

What does USB use to encode data?

the NRZI line coding

To ensure a minimum density of signal transitions  remains in the bitsream, what does USB use?

bit stuffing


A USB packet's end, called EOP (end-of-packet), is indicated by the transmitter driving 2 bit times of SE0 (D+ and D− both below max.) and 1 bit time of J state. After this, the transmitter ceases to drive the D+/D− lines and the aforementioned pull up resistors hold it in the J (idle) state. Sometimes skew due to hubs can add as much as one bit time before the SE0 of the end of packet. This extra bit can also result in a "bit stuff violation" if the six bits before it in the CRC are 1s. This bit should be ignored by receiver.

What is a USB packet's end called?

EOP (end-of-packet)

What can skew due to hubs add?

as much as one bit time before the SE0 of the end of packet

What can this extra bit result in?

"bit stuff violation


USB 2.0 devices use a special protocol during reset, called chirping, to negotiate the high bandwidth mode with the host/hub. A device that is HS capable first connects as an FS device (D+ pulled high), but upon receiving a USB RESET (both D+ and D− driven LOW by host for 10 to 20 ms) it pulls the D− line high, known as chirp K. This indicates to the host that the device is high bandwidth. If the host/hub is also HS capable, it chirps (returns alternating J and K states on D− and D+ lines) letting the device know that the hub operates at high bandwidth. The device has to receive at least three sets of KJ chirps before it changes to high bandwidth terminations and begins high bandwidth signaling. Because USB 3.0 uses wiring separate and additional to that used by USB 2.0 and USB 1.x, such bandwidth negotiation is not required.

What type of protocol is used for USB 2.0 devices during a reset?

a special protocol

What is the special protocol during a USB 2.0 device reset called?

chirping

A device that is HS capable first connects as a what?

an FS device (D+ pulled high)


According to routine testing performed by CNet, write operations to typical Hi-Speed (USB 2.0) hard drives can sustain rates of 25–30 MB/s, while read operations are at 30–42 MB/s; this is 70% of the total available bus bandwidth. For USB 3.0, typical write speed is 70–90 MB/s, while read speed is 90–110 MB/s. Mask Tests, also known as Eye Diagram Tests, are used to determine the quality of a signal in the time domain. They are defined in the referenced document as part of the electrical test description for the high-speed (HS) mode at 480 Mbit/s.

Write operations to typical Hi-Speed hard drives can what?

sustain rates of 25–30 MB/s,

For USB 3.0, typical write speed is what?

70–90 MB/s

What is the read speed for USB 3.0?

90–110 MB/s


After the sync field, all packets are made of 8-bit bytes, transmitted least-significant bit first. The first byte is a packet identifier (PID) byte. The PID is actually 4 bits; the byte consists of the 4-bit PID followed by its bitwise complement. This redundancy helps detect errors. (Note also that a PID byte contains at most four consecutive 1 bits, and thus never needs bit-stuffing, even when combined with the final 1 bit in the sync byte. However, trailing 1 bits in the PID may require bit-stuffing within the first few bits of the payload.)

After the sync field, all packets are made of how many bit bytes?

8-bit bytes

How are the bit bytes transmitted?

least-significant bit first

The first byte is what?

a packet identifier (PID) byte


Handshake packets consist of only a single PID byte, and are generally sent in response to data packets. Error detection is provided by transmitting four bits that represent the packet type twice, in a single PID byte using complemented form. Three basic types are ACK, indicating that data was successfully received, NAK, indicating that the data cannot be received and should be retried, and STALL, indicating that the device has an error condition and cannot transfer data until some corrective action (such as device initialization) occurs.

Handshake packets consist of only a single what?

PID byte

When are handshake packets generally sent?

in response to data packets

What is provided by transmitting four bits that represent the packet type twice, in a single PID byte using complemented form?

Error detection


IN and OUT tokens contain a seven-bit device number and four-bit function number (for multifunction devices) and command the device to transmit DATAx packets, or receive the following DATAx packets, respectively. An IN token expects a response from a device. The response may be a NAK or STALL response, or a DATAx frame. In the latter case, the host issues an ACK handshake if appropriate. An OUT token is followed immediately by a DATAx frame. The device responds with ACK, NAK, NYET, or STALL, as appropriate.

IN and OUT tokens contain what?

a seven-bit device number and four-bit function number

An IN token expects what?

a response from a device

An OUT token is followed immediately by a what?

DATAx frame


USB 2.0 also added a larger three-byte SPLIT token with a seven-bit hub number, 12 bits of control flags, and a five-bit CRC. This is used to perform split transactions. Rather than tie up the high-bandwidth USB bus sending data to a slower USB device, the nearest high-bandwidth capable hub receives a SPLIT token followed by one or two USB packets at high bandwidth, performs the data transfer at full or low bandwidth, and provides the response at high bandwidth when prompted by a second SPLIT token.

 a larger three-byte SPLIT token with a seven-bit hub number, 12 bits of control flags, and a five-bit CRC were created to do what?

to perform split transactions

Rather than tie up the high-bandwidth USB bus sending data to a slower USB device, what happens?

the nearest high-bandwidth capable hub receives a SPLIT token followed by one or two USB packets at high bandwidth

How many bits of control flags did USB 2.0 add?

12 bits


There are two basic forms of data packet, DATA0 and DATA1. A data packet must always be preceded by an address token, and is usually followed by a handshake token from the receiver back to the transmitter. The two packet types provide the 1-bit sequence number required by Stop-and-wait ARQ. If a USB host does not receive a response (such as an ACK) for data it has transmitted, it does not know if the data was received or not; the data might have been lost in transit, or it might have been received but the handshake response was lost.

There are two basic forms of data packet, what are they?

DATA0 and DATA1

A data packet must always be preceded by what?

an address token

What is a data packet usually followed by?

a handshake token from the receiver back to the transmitter


Low-bandwidth devices are supported with a special PID value, PRE. This marks the beginning of a low-bandwidth packet, and is used by hubs that normally do not send full-bandwidth packets to low-bandwidth devices. Since all PID bytes include four 0 bits, they leave the bus in the full-bandwidth K state, which is the same as the low-bandwidth J state. It is followed by a brief pause, during which hubs enable their low-bandwidth outputs, already idling in the J state. Then a low-bandwidth packet follows, beginning with a sync sequence and PID byte, and ending with a brief period of SE0. Full-bandwidth devices other than hubs can simply ignore the PRE packet and its low-bandwidth contents, until the final SE0 indicates that a new packet follows.

Low-bandwidth devices are supported with what?

a special PID value, PRE

All PID bytes include how many 0 bits?

four 0 bits

Full-bandwidth devices other than hubs can what?

simply ignore the PRE packet and its low-bandwidth contents


These and other differences reflect the differing design goals of the two buses: USB was designed for simplicity and low cost, while FireWire was designed for high performance, particularly in time-sensitive applications such as audio and video. Although similar in theoretical maximum transfer rate, FireWire 400 is faster than USB 2.0 Hi-Bandwidth in real-use, especially in high-bandwidth use such as external hard-drives. The newer FireWire 800 standard is twice as fast as FireWire 400 and faster than USB 2.0 Hi-Bandwidth both theoretically and practically. However, Firewire's speed advantages rely on low-level techniques such as direct memory access (DMA), which in turn have created opportunities for security exploits such as the DMA attack.

These and other differences reflect the differing design goals of what?

two buses

USB was designed for what?

simplicity and low cost

FireWire was designed for what?

high performance, particularly in time-sensitive applications such as audio and video

FireWire 400 is faster than what?

USB 2.0 Hi-Bandwidth in real-use


The IEEE 802.3af Power over Ethernet (PoE) standard specifies a more elaborate power negotiation scheme than powered USB. It operates at 48 V DC and can supply more power (up to 12.95 W, PoE+ 25.5 W) over a cable up to 100 meters compared to USB 2.0, which provides 2.5 W with a maximum cable length of 5 meters. This has made PoE popular for VoIP telephones, security cameras, wireless access points and other networked devices within buildings. However, USB is cheaper than PoE provided that the distance is short, and power demand is low.

The IEEE 802.3af Power over Ethernet (PoE) standard specifies a what?

more elaborate power negotiation scheme than powered USB

Is USB cheaper or more expensive than PoE?

cheaper

What keeps USB cheaper than PoE?

the distance is short, and power demand is low.


Ethernet standards require electrical isolation between the networked device (computer, phone, etc.) and the network cable up to 1500 V AC or 2250 V DC for 60 seconds. USB has no such requirement as it was designed for peripherals closely associated with a host computer, and in fact it connects the peripheral and host grounds. This gives Ethernet a significant safety advantage over USB with peripherals such as cable and DSL modems connected to external wiring that can assume hazardous voltages under certain fault conditions.

USB  was designed for peripherals to be what?

closely associated with a host computer

USB connects what?

the peripheral and host grounds

Ethernet standards require what?

isolation between the networked device (computer, phone, etc.) and the network cable up to 1500 V AC or 2250 V DC for 60 seconds


eSATA does not supply power to external devices. This is an increasing disadvantage compared to USB. Even though USB 3.0's 4.5 W is sometimes insufficient to power external hard drives, technology is advancing and external drives gradually need less power, diminishing the eSATA advantage. eSATAp (power over eSATA; aka ESATA/USB) is a connector introduced in 2009 that supplies power to attached devices using a new, backward compatible, connector. On a notebook eSATAp usually supplies only 5 V to power a 2.5-inch HDD/SSD; on a desktop workstation it can additionally supply 12 V to power larger devices including 3.5-inch HDD/SSD and 5.25-inch optical drives.

eSATA does not supply power to what?

external devices

Even though USB 3.0's 4.5 W is sometimes insufficient to power external hard drives, technology is what?

advancing and external drives gradually need less power

On a notebook eSATAp usually supplies how much power?

5 V to power a 2.5-inch HDD/SSD


USB 2.0 High-Speed Inter-Chip (HSIC) is a chip-to-chip variant of USB 2.0 that eliminates the conventional analog transceivers found in normal USB. It was adopted as a standard by the USB Implementers Forum in 2007. The HSIC physical layer uses about 50% less power and 75% less board area compared to traditional USB 2.0. HSIC uses two signals at 1.2 V and has a throughput of 480 Mbit/s. Maximum PCB trace length for HSIC is 10 cm. It does not have low enough latency to support RAM memory sharing between two chips.

USB 2.0 High-Speed Inter-Chip (HSIC) is a what?

chip-to-chip variant of USB 2.0

What does USB 2.0 High-Speed Inter-Chip eliminate?

the conventional analog transceivers found in normal USB

When was the USB 2.0 High-Speed Inter-Chip adopted as the standard by the USB Implementers Forum


Throughout its prehistory and early history, the region and its vicinity in the Yangtze region was the cradle of unique local civilizations which can be dated back to at least the 15th century BC and coinciding with the later years of the Shang and Zhou dynasties in North China. Sichuan was referred to in ancient Chinese sources as Ba-Shu (巴蜀), an abbreviation of the kingdoms of Ba and Shu which existed within the Sichuan Basin. Ba included Chongqing and the land in eastern Sichuan along the Yangtze and some tributary streams, while Shu included today's Chengdu, its surrounding plain and adjacent territories in western Sichuan.

What was Sichuan referred to as by ancient Chinese sources?

Ba-Shu

How far back can civilizations in the Yangtze region be dated?

at least the 15th century BC

Where were the kingdoms of Ba and Shu located?

within the Sichuan Basin

What land was included in the kingdom of Ba?

Chongqing and the land in eastern Sichuan along the Yangtze and some tributary streams

What land was included in the kingdom of Shu?

Chengdu, its surrounding plain and adjacent territories in western Sichuan

What dates bsck to the 1500's BC on the Yangtze region?

I'm not sure.

What dates to the early Shang and Zhou dynasties?

I'm not sure.

What dynasties ruled in the Central China Yangtze region?

I'm not sure.

What was Ba-Shu referred to in ancient Chinese?

I'm not sure.

What was the Zhou dynasty referred to as by Chinese sources?

I'm not sure.

How far back can civilizations in the Changdu region be dated?

I'm not sure.

Where were the kingdoms of Shang and Zhou located?

I'm not sure.

What ancient Chinese history was included in the kindgom of Shu?

I'm not sure.

What ancient Chinese history was included in the kingdom of Ba?

I'm not sure.


The existence of the early state of Shu was poorly recorded in the main historical records of China. It was, however, referred to in the Book of Documents as an ally of the Zhou. Accounts of Shu exist mainly as a mixture of mythological stories and historical legends recorded in local annals such as the Chronicles of Huayang compiled in the Jin dynasty (265–420), with folk stories such as that of Emperor Duyu (杜宇) who taught the people agriculture and transformed himself into a cuckoo after his death. The existence of a highly developed civilization with an independent bronze industry in Sichuan eventually came to light with an archaeological discovery in 1986 at a small village named Sanxingdui in Guanghan, Sichuan. This site, believed to be an ancient city of Shu, was initially discovered by a local farmer in 1929 who found jade and stone artefacts. Excavations by archaeologists in the area yielded few significant finds until 1986 when two major sacrificial pits were found with spectacular bronze items as well as artefacts in jade, gold, earthenware, and stone. This and other discoveries in Sichuan contest the conventional historiography that the local culture and technology of Sichuan were undeveloped in comparison to the technologically and culturally "advanced" Yellow River valley of north-central China. The name Shu continues to be used to refer to Sichuan in subsequent periods in Chinese history up to the present day.

What did Emperor  Duyu transform himself into after his death?

a cuckoo

What does the name Shu refer to?

Sichuan in subsequent periods in Chinese history up to the present day.

When was the site believed to be ancient city of Shu discovered, and by whom?

a local farmer in 1929

The Shu were an ally of who, according to the Book of Documents?

the Zhou

When were the Chronicles of Huayang compiled?

the Jin dynasty (265–420)

What civilization is well documented in China's historical records?

I'm not sure.

What book is one of the only written refrences to Zhou?

I'm not sure.

What local annual refers to Zhou in a mixture of myths and historical legends?

I'm not sure.

What iron age city was discovered in 1986?

I'm not sure.

What civilization was Sichuan less developed than?

I'm not sure.


The rulers of the expansionist Qin dynasty, based in present-day Gansu and Shaanxi, were only the first strategists to realize that the area's military importance matched its commercial and agricultural significance. The Sichuan basin is surrounded by the Himalayas to the west, the Qin Mountains to the north, and mountainous areas of Yunnan to the south. Since the Yangtze flows through the basin and then through the perilous Yangzi Gorges to eastern and southern China, Sichuan was a staging area for amphibious military forces and a refuge for political refugees.[citation needed]

What surrounds the Sichuan basin to the west?

the Himalayas

What mountains surround the Sichuan basin to the North?

Qin Mountains

What river flows through the Sichuan basin?

Yangtze

Where was the Qin dynasty based?

present-day Gansu and Shaanxi

What surrounds the Sichuan basin to the South?

mountainous areas of Yunnan

What mountain range surrounds the entire Sichuan Basin?

I'm not sure.

What dynasty was based in the Himalayas?

I'm not sure.

What river flows south of the Sichuan basin?

I'm not sure.

What mountain range was a staging area for military forces?

I'm not sure.

What surrounds the Sichuan basin to the east?

I'm not sure.

What mountains surround the China basin to the North?

I'm not sure.

What river flows through the China basin?

I'm not sure.

Where was the Yangtze dynasty based?

I'm not sure.

What surrounds the China basin to the South?

I'm not sure.


Qin armies finished their conquest of the kingdoms of Shu and Ba by 316 BC. Any written records and civil achievements of earlier kingdoms were destroyed. Qin administrators introduced improved agricultural technology. Li Bing, engineered the Dujiangyan irrigation system to control the Min River, a major tributary of the Yangtze. This innovative hydraulic system was composed of movable weirs which could be adjusted for high or low water flow according to the season, to either provide irrigation or prevent floods. The increased agricultural output and taxes made the area a source of provisions and men for Qin's unification of China.

By what year did the Qin armies finish their conquest of Shu and Ba?

316 BC

What did Qin administrators introduce to Shu and Ba?

improved agricultural technology.

Who engineered the Dujiangyan irrigation system to control the Min River?

Li Bing

The Min River is a major tributary of what river?

Yangtze

The Dujiangyan irrigation system was used for what purpose?

to either provide irrigation or prevent floods.

Who began their conquest of Shu and Ba in 316 BC?

I'm not sure.

What was preserved during the Qin conquest?

I'm not sure.

Who tried to control the Yangtze river?

I'm not sure.

What was built to control the Yangtze river?

I'm not sure.

The Yantze is a major tributary of what river?

I'm not sure.

By what year did the Quin armies finish their conquest of Yangtze?

I'm not sure.

What did Qin administrators introduce to Yangtze?

I'm not sure.

Who engineered the Dujangyan irrigation sytem to control China?

I'm not sure.

The Qin River is a major tributary of what river?

I'm not sure.

The Min irrigation system was used for what purpose?

I'm not sure.


Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.

During which dynasty did Sichuan regain its political and cultural prominence for which it was known during the Han?

Tang dynasty

Who was known as China's greatest poet and lived in Chengdu?

Du Fu

What was Chengu known to supply the country with?

armies

Which years saw the An Lushan Rebellion?

Which empire ravished the Chengdu region with constant warfare and economic distress?

the Tibetan Empire

Who regained their prominence under the Sui dynasty?

I'm not sure.

Who came under tight control during the Tang dynasty?

I'm not sure.

What revolt took place in the 7th century?

I'm not sure.

Who fled from Sichuan to Chang'an?

I'm not sure.

What region was liberated by the Tibetan Empire?

I'm not sure.

During which dynasty did Sichuan regain its political and cultural prominence for which it was known during the Tibetan Empire?

I'm not sure.

Who was known as China's greatest poet and lived in Tang?

I'm not sure.

What was Chengu known to supply the Tibetan Empire with?

I'm not sure.

Which years saw the Han Rebellion?

I'm not sure.

Which empire ravished the Lushan region with constant warfare and economic distress?

I'm not sure.


In the middle of the 17th century, the peasant rebel leader Zhang Xianzhong (1606–1646) from Yan'an, Shanxi Province, nicknamed Yellow Tiger, led his peasant troop from north China to the south, and conquered Sichuan. Upon capturing it, he declared himself emperor of the Daxi Dynasty (大西王朝). In response to the resistance from local elites, he massacred a large native population. As a result of the massacre as well as years of turmoil during the Ming-Qing transition, the population of Sichuan fell sharply, requiring a massive resettlement of people from the neighboring Huguang Province (modern Hubei and Hunan) and other provinces during the Qing dynasty.

What was the nickname rebel leader Zhang Xianzhong?

Yellow Tiger

Which region did Yellow Tiger conquer in the mid-17th century?

Sichuan

Which dynasty did Yellow Tiger declare himself the emperor of?

Daxi Dynasty

Which province supplied a large amount of people to the Sichuan resettlement, following years of turmoil during the Ming-Qing transition?

Huguang Province

Who lead the peasant rebelion in the mid 1700's?

I'm not sure.

Where was the rebel leader born in the 16th century from?

I'm not sure.

What was the nickname of the man who led the rebelion in the 1700's?

I'm not sure.

Who conquered the Daxi Dynasty?

I'm not sure.

During what dynasty did the population of Schuan rise sharply?

I'm not sure.

What was the nickname revel leader Daxi Dynasty?

I'm not sure.

Which region did Huguang conquer in the mid-17th century?

I'm not sure.

Which Dynasty did Huguang declare himself an emperor of?

I'm not sure.

Which province supplied a large amount of troops to the Sichuan resettlement, following years of turmoil during the Ming-Qing transition?

I'm not sure.

Why did the population of Yellow Tiger fall?

I'm not sure.


In the 20th century, as Beijing, Shanghai, Nanjing, and Wuhan had all been occupied by the Japanese during the Second Sino-Japanese War, the capital of the Republic of China had been temporary relocated to Chongqing, then a major city in Sichuan. An enduring legacy of this move is that nearby inland provinces, such as Shaanxi, Gansu, and Guizhou, which previously never had modern Western-style universities, began to be developed in this regard. The difficulty of accessing the region overland from the eastern part of China and the foggy climate hindering the accuracy of Japanese bombing of the Sichuan Basin, made the region the stronghold of Chiang Kai-Shek's Kuomintang government during 1938-45, and led to the Bombing of Chongqing.

To which city was the Chinese capitol relocated to during Japanese occupation in the 20th century?

Chongqing

What are some major cities occupied by the Chinese during the Second Sino-Japanese War?

Beijing, Shanghai, Nanjing, and Wuhan

What are some inland provinces that began to develop modern, westernized education systems?

Shaanxi, Gansu, and Guizhou

What are some reasons for the lack of accurate Japanese bombing during the Second Sino-Japanese War in the Sichuan Basin?

The difficulty of accessing the region overland from the eastern part of China and the foggy climate

What regions where occuppied dring the first Sino-Japanese War?

I'm not sure.

Where was the capital relocated to during the First Sino-Japanese War?

I'm not sure.

What caused inland provinces to lose Western-style universities?

I'm not sure.

What made the Sichuan basin suseptable to bombing?

I'm not sure.

Who fled the area during 1938-45?

I'm not sure.

To which city was the Gansu capitol relocated to during Japanese occupation in the 20th century?

I'm not sure.

What are some major cities occupied by the Chinese during the foggy climate?

I'm not sure.

What are some inland provinces that began to develop major cities?

I'm not sure.

What are some reasons for the lack of accurate Japanese capitals the Second Sino-Japanese War in the Sichuan Basin?

I'm not sure.

When was Guizhou the stronghold of Chiang Kai-Shek Koumintang's government?

I'm not sure.


The Second Sino-Japanese War was soon followed by the resumed Chinese Civil War, and the cities of East China fell to the Communists one after another, the Kuomintang government again tried to make Sichuan its stronghold on the mainland, although it already saw some Communist activity since it was one area on the road of the Long March. Chiang Kai-Shek himself flew to Chongqing from Taiwan in November 1949 to lead the defense. But the same month Chongqing fell to the Communists, followed by Chengdu on 10 December. The Kuomintang general Wang Sheng wanted to stay behind with his troops to continue anticommunist guerilla war in Sichuan, but was recalled to Taiwan. Many of his soldiers made their way there as well, via Burma.

What group was the main antagonist during the Chinese Civil War?

the Communists

Who led the defense of Chongqing in November 1949?

Chiang Kai-Shek

On what date in 1949 did Chengdu fall to the communists?

10 December

Why did Sichuan see some communist activity?

it was one area on the road of the Long March

What resumed after the First Sino-Japanese War?

I'm not sure.

What happened to the cities of west China?

I'm not sure.

What government fled sichuan again?

I'm not sure.

Who flew from Chongqing to Tawian to lead the defense in 1949?

I'm not sure.

What other city fell following the fall of Chendu?

I'm not sure.

What group was the on the defense during the Chinese Civil War?

I'm not sure.

Who led the defense of Burma in November 1949?

I'm not sure.

On what date in 1949 did Changdu fall to Chiang Kai-Shek?

I'm not sure.

Why did Sichuan see some strongholds on the mainland?

I'm not sure.

Which government tried to make Burma its stronghold?

I'm not sure.


From 1955 until 1997 Sichuan had been China's most populous province, hitting 100 million mark shortly after the 1982 census figure of 99,730,000. This changed in 1997 when the Sub-provincial city of Chongqing as well as the three surrounding prefectures of Fuling, Wanxian, and Qianjiang were split off into the new Chongqing Municipality. The new municipality was formed to spearhead China's effort to economically develop its western provinces, as well as to coordinate the resettlement of residents from the reservoir areas of the Three Gorges Dam project.

What Chinese Province had the largest population until 1997?

Sichuan

Why did Sichuan lose its status as the most populous Province in 1997?

Chongqing as well as the three surrounding prefectures of Fuling, Wanxian, and Qianjiang were split off into the new Chongqing Municipality.

Why was the Chongqing Municipality formed?

to spearhead China's effort to economically develop its western provinces

Why did China need to resettle people into Chongqing?

the Three Gorges Dam project.

What was the population of Sichuan in 1982?

During what period was Sichuan China's most sparsley populated area?

I'm not sure.

What provinces where combined in 1997?

I'm not sure.

Who was trying to develop its eastern provinces?

I'm not sure.

Why were some municipalities eliminated?

I'm not sure.

What Chinese Province had the largest population until 1955?

I'm not sure.

Why did Sichuan lose its status as the most populous Province in 1955?

I'm not sure.

Why was the Quianjiang Municipality formed?

I'm not sure.

Why did China need to resettle people into Gorges?

I'm not sure.

What was the population of Sichuan in 1955?

I'm not sure.


Sichuan consists of two geographically very distinct parts. The eastern part of the province is mostly within the fertile Sichuan basin (which is shared by Sichuan with Chongqing Municipality). The western Sichuan consists of the numerous mountain ranges forming the easternmost part of the Qinghai-Tibet Plateau, which are known generically as Hengduan Mountains. One of these ranges, Daxue Mountains, contains the highest point of the province Gongga Shan, at 7,556 metres (24,790 ft) above sea level.

How many distinct parts make up Sichuan?

two

What makes up majority of the eastern Sichuan province?

Sichuan basin

Western Sichuan is delineated by what mountain range?

Hengduan Mountains

Which mountain range contains the highest point in the Gongga Shan province?

Daxue Mountains

How many feet above sea level is the highest point of the Saxue Mountains?

24,790 ft

What province has similar eastern and western parts?

I'm not sure.

What is formed by the mountains in eastern Sichuan?

I'm not sure.

What basin covers most of western Sichuan?

I'm not sure.

What mountain range in eastern Sichuan contains the highest point of the province?

I'm not sure.

How many distinct parts make up Tibet?

I'm not sure.

What makes up majority of the eastern Qinghai province?

I'm not sure.

Which mountain range contains the highest point in the Chongquing province?

I'm not sure.

Which mountain range contains the highest point in the Qinghai province?

I'm not sure.

How many feet above sea level is the highest point of the Hangduan Mountains?

I'm not sure.


The Yangtze River and its tributaries flows through the mountains of western Sichuan and the Sichuan Basin; thus, the province is upstream of the great cities that stand along the Yangtze River further to the east, such as Chongqing, Wuhan, Nanjing and Shanghai. One of the major tributaries of the Yangtze within the province is the Min River of central Sichuan, which joins the Yangtze at Yibin. Sichuan's 4 main rivers, as Sichuan means literally, are Jaling Jiang, Tuo Jiang, Yalong Jiang, and Jinsha Jiang.

Which river flows through the Sichuan Basin?

Yangtze River

Which tributary of the Yangtze flows through central Sichuan?

Min River

What are the 4 main rivers in Sichuan?

Jaling Jiang, Tuo Jiang, Yalong Jiang, and Jinsha Jiang

Name some cities downstream of the Yangtze river that are to the east of Sichuan.

Chongqing, Wuhan, Nanjing and Shanghai

What river flows through eastern Sichuan?

I'm not sure.

What province is downstream from the large cities along the Yangtze?

I'm not sure.

what cities are west of Sichuan?

I'm not sure.

The Yangtze is a trubutary of what river?

I'm not sure.

Which river flows through the Nanjing Basin?

I'm not sure.

Which tributary of the Yangtze flows through central Jaling Jaling?

I'm not sure.

What are the 4 main rivers in Chongquing?

I'm not sure.

Name some cities downstream of the Yangtze river that are to the west of Sichuan?

I'm not sure.

What joins the Wuhan at Yibin?

I'm not sure.


Due to great differences in terrain, the climate of the province is highly variable. In general it has strong monsoonal influences, with rainfall heavily concentrated in the summer. Under the Köppen climate classification, the Sichuan Basin (including Chengdu) in the eastern half of the province experiences a humid subtropical climate (Köppen Cwa or Cfa), with long, hot, humid summers and short, mild to cool, dry and cloudy winters. Consequently, it has China's lowest sunshine totals. The western region has mountainous areas producing a cooler but sunnier climate. Having cool to very cold winters and mild summers, temperatures generally decrease with greater elevation. However, due to high altitude and its inland location, many areas such as Garze County and Zoige County in Sichuan exhibit a subarctic climate (Köppen Dwc)- featuring extremely cold winters down to -30 °C and even cold summer nights. The region is geologically active with landslides and earthquakes. Average elevation ranges from 2,000 to 3,500 meters; average temperatures range from 0 to 15 °C. The southern part of the province, including Panzhihua and Xichang, has a sunny climate with short, very mild winters and very warm to hot summers.

What climate classification does the Sichuan Basin hold?

humid subtropical climate

What area of China has the least amount of sunlight?

the Sichuan Basin

Garze County and Zoige County in Sichuan experience what kind of climate?

subarctic climate

What is the range of average elevation in the Sichuan Basin?

2,000 to 3,500 meters

What is the range of average temperature in the Sichuan Basin?

0 to 15 °C

What basin area has a humid tropical climate?

I'm not sure.

What area of China has the least amount of sunlight?

I'm not sure.

What two counties have an arctic climate?

I'm not sure.

Whare is the average elevation 2,000 tp 3.000 miles?

I'm not sure.

What climate classification does the Garze Basin hold?

I'm not sure.

What area of China has the least amount of earthquakes?

I'm not sure.

What kind of climate does Koppen County in Sichuan experience?

I'm not sure.

What is the range of average elevation in the Garze Basin?

I'm not sure.

What is the range of average temperature in the Garze Basin?

I'm not sure.


Sichuan has been historically known as the "Province of Abundance". It is one of the major agricultural production bases of China. Grain, including rice and wheat, is the major product with output that ranked first in China in 1999. Commercial crops include citrus fruits, sugar cane, sweet potatoes, peaches and grapes. Sichuan also had the largest output of pork among all the provinces and the second largest output of silkworm cocoons in 1999. Sichuan is rich in mineral resources. It has more than 132 kinds of proven underground mineral resources including vanadium, titanium, and lithium being the largest in China. The Panxi region alone possesses 13.3% of the reserves of iron, 93% of titanium, 69% of vanadium, and 83% of the cobalt of the whole country. Sichuan also possesses China's largest proven natural gas reserves, the majority of which is transported to more developed eastern regions.

What area for the "Province of Abundance" refer to?

Sichuan

What are the major agricultural outputs of Sichuan?

rice and wheat

What kind of meat is Sichuan known to produce in abundance?

pork

How much of China's titanium is houses in Sichuan?

What is often done with Sichuan's natural gas reserves?

transported to more developed eastern regions

What is known as the Bread Basket of China?

I'm not sure.

What area produces the most silkworm?

I'm not sure.

What reserves does Sichuan send further west?

I'm not sure.

What region contains 69% of the titanium  reserves?

I'm not sure.

What silkworm cocoon does the "Province of Abundance" refer to?

I'm not sure.

What are the major agricultural outputs of Providence?

I'm not sure.

What kind of meat is the Providence known to produce in abundance?

I'm not sure.

How much of Providence's titanium is housed in Sichuan?

I'm not sure.

What is often done with Sichuan's pork?

I'm not sure.


Sichuan is one of the major industrial centers of China. In addition to heavy industries such as coal, energy, iron and steel, the province has also established a light industrial sector comprising building materials, wood processing, food and silk processing. Chengdu and Mianyang are the production centers for textiles and electronics products. Deyang, Panzhihua, and Yibin are the production centers for machinery, metallurgical industries, and wine, respectively. Sichuan's wine production accounted for 21.9% of the country’s total production in 2000.

What are some major industrial outputs of Sichuan?

coal, energy, iron and steel

What areas are major areas of production for textiles and electronics?

Chengdu and Mianyang

How much of China's wine did Sichuan produce in 2000?

Which city in Sichuan is known for its machinery production?

Deyang

Which city in Sichuan is known for its metallurgical industries?

Panzhihua

What is a major industrial center of Asia?

I'm not sure.

How much of Asia's wine did Sichuan produce in 2000?

I'm not sure.

What is produced in Chengdu besides machinery?

I'm not sure.

What is produced in Yibin besides textiles?

I'm not sure.

What are some major industrial outputs of food?

I'm not sure.

What areas are major building materials for textiles and electronics?

I'm not sure.

How much of Chinas wine did light industrial sectors produce in 2000?

I'm not sure.

Which city in Sichuan is known for its building materials?

I'm not sure.

Which city in Yibin is known for its metallurgical industries?

I'm not sure.


The Three Gorges Dam, the largest dam ever constructed, is being built on the Yangtze River in nearby Hubei province to control flooding in the Sichuan Basin, neighboring Yunnan province, and downstream. The plan is hailed by some as China's efforts to shift towards alternative energy sources and to further develop its industrial and commercial bases, but others have criticised it for its potentially harmful effects, such as massive resettlement of residents in the reservoir areas, loss of archeological sites, and ecological damages.

What is the largest dam ever built in the world?

Three Gorges Dam

On which river is the Three Gorges Dam built?

Yangtze River

What is the purpose of the Three Gorges Dam?

to control flooding in the Sichuan Basin, neighboring Yunnan province, and downstream

What are some reasons for the opposition of the Three Gorges Dam?

massive resettlement of residents in the reservoir areas, loss of archeological sites, and ecological damages.

What is the second largest damn in China?

I'm not sure.

What is being built to control flooding in the Hubei province?

I'm not sure.

China improving its industrial base is a negative effect of what?

I'm not sure.

What is the largest ever built in commercial bases?

I'm not sure.

On which river are alternative energy sources built?

I'm not sure.

What is the purpose of the resettlement of residents?

I'm not sure.

What are some reasons for the opposition of the alternative energy sources?

I'm not sure.

What on the Yangtze River is being damaged?

I'm not sure.


According to the Sichuan Department of Commerce, the province's total foreign trade was US$22.04 billion in 2008, with an annual increase of 53.3 percent. Exports were US$13.1 billion, an annual increase of 52.3 percent, while imports were US$8.93 billion, an annual increase of 54.7 percent. These achievements were accomplished because of significant changes in China's foreign trade policy, acceleration of the yuan's appreciation, increase of commercial incentives and increase in production costs. The 18 cities and counties witnessed a steady rate of increase. Chengdu, Suining, Nanchong, Dazhou, Ya'an, Abazhou, and Liangshan all saw an increase of more than 40 percent while Leshan, Neijiang, Luzhou, Meishan, Ziyang, and Yibin saw an increase of more than 20 percent. Foreign trade in Zigong, Panzhihua, Guang'an, Bazhong and Ganzi remained constant.

By how much did foreign trade increase in Sichuan in 2008?

53.3 percent

What was the export level of Sichuan in 2008?

US$13.1 billion

What was the import level of Sichuan in 2008?

US$8.93 billion

What cities saw an increase in foreign trade of more than 40% in 2008?

Chengdu, Suining, Nanchong, Dazhou, Ya'an, Abazhou, and Liangshan

Who says Sichuans total forign trade is 22.04 billion CNY

I'm not sure.

What was equal to 13.1 billion CNY?

I'm not sure.

What was equal to 8.93 billion CNY?

I'm not sure.

What has a decrease in production costs contributed to?

I'm not sure.

By how much did production costs increase in Sichuan in 2008?

I'm not sure.

What were the commercial incentives for of Sichuan in 2008?

I'm not sure.

What production costs of Sichuan in 2008?

I'm not sure.

What cities saw an increase in imports of more than 40% in 2008?

I'm not sure.

What caused the increase in foreign counties?

I'm not sure.


The Sichuan government raised the minimum wage in the province by 12.5 percent at the end of December 2007. The monthly minimum wage went up from 400 to 450 yuan, with a minimum of 4.9 yuan per hour for part-time work, effective 26 December 2007. The government also reduced the four-tier minimum wage structure to three. The top tier mandates a minimum of 650 yuan per month, or 7.1 yuan per hour. National law allows each province to set minimum wages independently, but with a floor of 450 yuan per month.

By how much did Sichuan increase minimum wage in December 2007?

12.5 percent

What was the new monthly minimum wage in Sichuan by January 2008?

450 yuan

What was the minimum hourly wage in Sichuan on December 28, 2007?

4.9 yuan

What is the national minimum monthly wage in China?

450 yuan per month

Who raised the minimum wage by 1.25%

I'm not sure.

Where is the maximum wage 4.9 yuan per hour?

I'm not sure.

who icreased the three tier minimum wage structure to four?

I'm not sure.

What law sets the minimum wage across China?

I'm not sure.

By how much did the top tier increase minimum wage in December 2007?

I'm not sure.

What was the new monthy minimum wage in the top tier by January 2008?

I'm not sure.

What was the minimum hourly wage in the top tier on December 28, 2007?

I'm not sure.

What was the national minimum monthly wage in the top tier?

I'm not sure.

What did the top tier reduce the four-tier minimum wage structure to?

I'm not sure.


Chengdu Economic and Technological Development Zone (Chinese: 成都经济技术开发区; pinyin: Chéngdū jīngjì jìshù kāifā qū) was approved as state-level development zone in February 2000. The zone now has a developed area of 10.25 km2 (3.96 sq mi) and has a planned area of 26 km2 (10 sq mi). Chengdu Economic and Technological Development Zone (CETDZ) lies 13.6 km (8.5 mi) east of Chengdu, the capital city of Sichuan Province and the hub of transportation and communication in southwest China. The zone has attracted investors and developers from more than 20 countries to carry out their projects there. Industries encouraged in the zone include mechanical, electronic, new building materials, medicine and food processing.

When was the Chengdu Economic and Technological Development Zone approved?

February 2000

What is the planned size of the Chengdu Economic and Technological Development Zone?

CETDZ

How far east of Chengdu is CETDZ?

8.5 mi

What is the capital city of Sichuan?

Chengdu

How many countries are represented by the investors and developers of the CETDZ?

What was approved as a national-level development zone in 2000?

I'm not sure.

What city east of the Chengu Economic and Technological Development Zone?

I'm not sure.

What has attracted investers from 20 other provinces?

I'm not sure.

When was the Chengdu Economic and Technological Development Zone approved in more than 20 countries?

I'm not sure.

Where planned food processing area lie?

I'm not sure.

How far east of Chengdu is the planned food processing area?

I'm not sure.

What is the capital city of China?

I'm not sure.

How many cities are represented by the investors and developers of the CETDZ?

I'm not sure.


Established in 1988, Chengdu Hi-tech Industrial Development Zone (Chinese: 成都高新技术产业开发区; pinyin: Chéngdū Gāoxīn Jìshù Chǎnyè Kāifā Qū) was approved as one of the first national hi-tech development zones in 1991. In 2000, it was open to APEC and has been recognized as a national advanced hi-tech development zone in successive assessment activities held by China's Ministry of Science and Technology. It ranks 5th among the 53 national hi-tech development zones in China in terms of comprehensive strength.

When was the Chengdu Hi-tech Industrial Development Zone established?

When was the Chengdu Hi-tech Industrial Development Zone approved?

The Chengdu Hi-tech Industrial Development Zone is what rank of 53 in China terms of comprehensive strength?

what was approved as a hi-tech development zone in 1988?

I'm not sure.

Wat development zone was established in 1991?

I'm not sure.

What ranks number 5 in world development zones?

I'm not sure.

When was the APEC Hi-tech Industrial Development Zone established?

I'm not sure.

When was the APEC Hi-tech Industrial Development Zone approved?

I'm not sure.

The Chengdu APEC is what rank of 53 in China terms of comprehensive strength?

I'm not sure.

What has been recognized as a pinyin?

I'm not sure.

How many national APEC zones are in China?

I'm not sure.


Chengdu Hi-tech Development Zone covers an area of 82.5 km2 (31.9 sq mi), consisting of the South Park and the West Park. By relying on the city sub-center, which is under construction, the South Park is focusing on creating a modernized industrial park of science and technology with scientific and technological innovation, incubation R&D, modern service industry and Headquarters economy playing leading roles. Priority has been given to the development of software industry. Located on both sides of the "Chengdu-Dujiangyan-Jiuzhaigou" golden tourism channel, the West Park aims at building a comprehensive industrial park targeting at industrial clustering with complete supportive functions. The West Park gives priority to three major industries i.e. electronic information, biomedicine and precision machinery.

Which Parks make up the Chengdu Hi-tech Development Zone?

South Park and the West Park

What is the focus of the South Park?

creating a modernized industrial park of science and technology

Which industries does West Park give priority to?

electronic information, biomedicine and precision machinery

What industry does South Park give priority to?

software industry

What development zone covers 82.5 square miles?

I'm not sure.

What is the West park doing by focusing on the city sub-center?

I'm not sure.

BWhat industry does South Park give priority to other than electronic informatiom?

I'm not sure.

Which Parks make up the incubation R&D?

I'm not sure.

What is the focus of the tourism channel?

I'm not sure.

Which industries do both sides give priority to?

I'm not sure.

What covers and area of 31.9 Km2?

I'm not sure.

What targets cities with complete supportive functions?

I'm not sure.


Mianyang Hi-Tech Industrial Development Zone was established in 1992, with a planned area of 43 km2 (17 sq mi). The zone is situated 96 kilometers away from Chengdu, and is 8 km (5.0 mi) away from Mianyang Airport. Since its establishment, the zone accumulated 177.4 billion yuan of industrial output, 46.2 billion yuan of gross domestic product, fiscal revenue 6.768 billion yuan. There are more than 136 high-tech enterprises in the zone and they accounted for more than 90% of the total industrial output.

What is the planned area of the Mianyang Hi-Tech Industrial Development Zone?

17 sq mi

What is the distance between the Mianyang Hi-Tech Industrial Development Zone and Mianyang Airport?

8 km

How much value has Mianyang Hi-Tech Industrial Development Zone  output since inception?

177.4 billion yuan

How many high-tech enterprises are present in the Mianyang Hi-Tech Industrial Development Zone ?

What zone icludes 43 square miles?

I'm not sure.

What city is the zone 8 km away from?

I'm not sure.

What airport is 96 km from the zone?

I'm not sure.

What enterprises make up 90% of China's industriall outpput?

I'm not sure.

What is the planned area of the Mianyang Airport?

I'm not sure.

What is the distance between the Mianyang Airport and Chengdu?

I'm not sure.

How much value has the Mianyang Airport output since inception?

I'm not sure.

How many high-tech enterprises are present in Chengdu?

I'm not sure.

How many zones accounted for more than 90% of total industrial output?

I'm not sure.


On 3 November 2007, the Sichuan Transportation Bureau announced that the Sui-Yu Expressway was completed after three years of construction. After completion of the Chongqing section of the road, the 36.64 km (22.77 mi) expressway connected Cheng-Nan Expressway and formed the shortest expressway from Chengdu to Chongqing. The new expressway is 50 km (31 mi) shorter than the pre-existing road between Chengdu and Chongqing; thus journey time between the two cities was reduced by an hour, now taking two and a half hours. The Sui-Yu Expressway is a four lane overpass with a speed limit of 80 km/h (50 mph). The total investment was 1.045 billion yuan.

How long did it take to complete the Sui-Yu Expressway?

three years

After the newest expressway was completed, what was the new travel time between Chengdu and Chongqing?

two and a half hours

What is the speed limit on the Sui-Yu Expressway?

80 km/h (50 mph)

What was the total cost of the Sui-Yu Expressway?

1.045 billion yuan

How many lanes make up the Sui-Yu Expressway?

four lane

What did construction begin on in Nov 2007?

I'm not sure.

What took 3 years of planning?

I'm not sure.

What was the longest espressway from Chengdu to Chongqing?

I'm not sure.

What is the expressway 50 km longer than?

I'm not sure.

How long did it take to complete the total investment?

I'm not sure.

After the newest expressway was completed, what was the new travel time between Chengdu and Cheng-Nan?

I'm not sure.

What is the speed limit on the Chengdu expressway?

I'm not sure.

What was the total cost of the Chengdu expressway?

I'm not sure.

How many lanes make up the Chengdu expressway?

I'm not sure.


The majority of the province's population is Han Chinese, who are found scattered throughout the region with the exception of the far western areas. Thus, significant minorities of Tibetan, Yi, Qiang and Nakhi people reside in the western portion that are impacted by inclement weather and natural disasters, environmentally fragile, and impoverished. Sichuan's capital of Chengdu is home to a large community of Tibetans, with 30,000 permanent Tibetan residents and up to 200,000 Tibetan floating population. The Eastern Lipo, included with either the Yi or the Lisu people, as well as the A-Hmao, also are among the ethnic groups of the provinces.

What race is the majority of Sichuan?

Han Chinese

What is one of the largest minorities in Chengdu?

Tibetan

Which part of Sichuan has the worst weather and subjected to natural disasters?

far western areas.

How many permanent Tibetan people live in Chengdu?

What group makes up a minority of the privinces population?

I'm not sure.

What groups live in the eastern province?

I'm not sure.

Where do people benefit from mild climate?

I'm not sure.

What population includes 200,000 perminant residents?

I'm not sure.

What race is the majority of Tibet?

I'm not sure.

What is one of the largest minorities in Yi?

I'm not sure.

Which part of Sichuan has the worst weather and subjected to ethnic groups?

I'm not sure.

How many permanent Tibetan people live in Eastern Lipo?

I'm not sure.

How big is the Yi floating population?

I'm not sure.


Sichuan was China's most populous province before Chongqing became a directly-controlled municipality; it is currently the fourth most populous, after Guangdong, Shandong and Henan. As of 1832, Sichuan was the most populous of the 18 provinces in China, with an estimated population at that time of 21 million. It was the third most populous sub-national entity in the world, after Uttar Pradesh, India and the Russian Soviet Federative Socialist Republic until 1991, when the Soviet Union was dissolved. It is also one of the only six to ever reach 100 million people (Uttar Pradesh, Russian RSFSR, Maharashtra, Sichuan, Bihar and Punjab). It is currently 10th.

What are the three most populist provinces in China?

Guangdong, Shandong and Henan

What was the population of Sichuan in 1832?

21 million

What is the tenth most populous sub-national entity in the world?

Sichuan

How many sub-national entities have surpassed 100 million people in total?

six

In what year was the Soviet Union disbanded?

What are the three most populous provinces in Russia?

I'm not sure.

What was the population of Maharashtra in 1832?

I'm not sure.

What is the tenth most populous sub-national entity in Henan?

I'm not sure.

How many sub-national entities have surpassed 21 million people in total?

I'm not sure.

In what year was China disbanded?

I'm not sure.


Garzê Tibetan Autonomous Prefecture and Ngawa Tibetan and Qiang Autonomous Prefecture in western Sichuan are populated by Tibetans and Qiang people. Tibetans speak the Khams and Amdo Tibetan, which are Tibetic languages, as well as various Qiangic languages. The Qiang speak Qiangic languages and often Tibetic languages as well. The Yi people of Liangshan Yi Autonomous Prefecture in southern Sichuan speak the Nuosu language, which is one of the Lolo-Burmese languages; Yi is written using the Yi script, a syllabary standardized in 1974. The Southwest University for Nationalities has one of China's most prominent Tibetology departments, and the Southwest Minorities Publishing House prints literature in minority languages. In the minority inhabited regions of Sichuan, there is bi-lingual signage and public school instruction in non-Mandarin minority languages.

What are the largest minorities of western Sichuan?

Tibetans and Qiang

What languages do Tibetans in Sichuan speak?

Khams and Amdo Tibetan

What language do the Yi people speak?

Nuosu

In what year was the language of the Yi people standardized?

Which University houses one of China's most prominent Tibetology departments?

Southwest University for Nationalities

What are the largest minorities of Southwest University for Nationalities?

I'm not sure.

What languages do Tibetans in Burma speak?

I'm not sure.

What language do the Mandarin people speak?

I'm not sure.

In what year was the language of the Mandarin people standardized?

I'm not sure.

Which University houses one of China's most prominent Burmese departments?

I'm not sure.


The Sichuanese are proud of their cuisine, known as one of the Four Great Traditions of Chinese cuisine. The cuisine here is of "one dish, one shape, hundreds of dishes, hundreds of tastes", as the saying goes, to describe its acclaimed diversity. The most prominent traits of Sichuanese cuisine are described by four words: spicy, hot, fresh and fragrant. Sichuan cuisine is popular in the whole nation of China, so are Sichuan chefs. Two well-known Sichuan chefs are Chen Kenmin and his son Chen Kenichi, who was Iron Chef Chinese on the Japanese television series "Iron Chef".

Who is proud of their chefs?

I'm not sure.

What is popular in the whole nation of Japan?

I'm not sure.

Who is Sichuan's son?

I'm not sure.

What are the most prominent traits of Japanese cuisine?

I'm not sure.

Who were featured on the Chinese television series "Iron Chef"?

I'm not sure.


Unicode is a computing industry standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. Developed in conjunction with the Universal Coded Character Set (UCS) standard and published as The Unicode Standard, the latest version of Unicode contains a repertoire of more than 120,000 characters covering 129 modern and historic scripts, as well as multiple symbol sets. The standard consists of a set of code charts for visual reference, an encoding method and set of standard character encodings, a set of reference data files, and a number of related items, such as character properties, rules for normalization, decomposition, collation, rendering, and bidirectional display order (for the correct display of text containing both right-to-left scripts, such as Arabic and Hebrew, and left-to-right scripts). As of June 2015[update], the most recent version is Unicode 8.0. The standard is maintained by the Unicode Consortium.

What was Unicode published as?

The Unicode Standard

What was unicode developed in conjunction with?

Universal Coded Character Set (UCS)

What is the most recent version of Unicode?

Unicode 8.0

Who maintains the Unicode Standard?

Unicode Consortium

Unicode contains how many thousands of characters in its repertoire?

120,000 characters

What is the Universal Coded Character set published as?

I'm not sure.

How many characters does Arabic have?

I'm not sure.

How many scripts does UCS cover?

I'm not sure.

What is the acronym for Unicode?

I'm not sure.

What is an example of a left-to-right script?

I'm not sure.


Unicode can be implemented by different character encodings. The most commonly used encodings are UTF-8, UTF-16 and the now-obsolete UCS-2. UTF-8 uses one byte for any ASCII character, all of which have the same code values in both UTF-8 and ASCII encoding, and up to four bytes for other characters. UCS-2 uses a 16-bit code unit (two 8-bit bytes) for each character but cannot encode every character in the current Unicode standard. UTF-16 extends UCS-2, using one 16-bit unit for the characters that were representable in UCS-2 and two 16-bit units (4 × 8 bits) to handle each of the additional characters.

What are the most commonly used encodings of Unicode?

UTF-8, UTF-16 and the now-obsolete UCS-2

What does UTF-8 use in terms of bytes?

UTF-8 uses one byte for any ASCII character

What type of code does UCS-2 use?

16-bit code unit

What does UTF-16 expand?

How are two 16-bit units used?

(4 × 8 bits

What are character encodings implemented by?

I'm not sure.

Which two encodings are now obsolete?

I'm not sure.

What did UCS-2 expand?

I'm not sure.

How many ASCII characters are used to make one UTF-8?

I'm not sure.

What system has a minimum of four bytes?

I'm not sure.


Unicode has the explicit aim of transcending the limitations of traditional character encodings, such as those defined by the ISO 8859 standard, which find wide usage in various countries of the world but remain largely incompatible with each other. Many traditional character encodings share a common problem in that they allow bilingual computer processing (usually using Latin characters and the local script), but not multilingual computer processing (computer processing of arbitrary scripts mixed with each other).

What is the aim of Unicode?

transcending the limitations of traditional character encodings

Traditional character encodings don't allow what type of computer processing?

multilingual computer processing

What is multilingual computer processing?

(computer processing of arbitrary scripts mixed with each other

Bilingual computer processing uses what characters?

usually using Latin characters

What is the major limitation of traditional character encodings?

wide usage in various countries of the world but remain largely incompatible with each other

What was Unicode defined in?

I'm not sure.

What characters does multilingual processors use?

I'm not sure.

What type of encodings do not allow bilingual computer processing?

I'm not sure.

What is the limitation of unicode globally?

I'm not sure.

What are traditional character encodings attempting to surpass?

I'm not sure.


The first 256 code points were made identical to the content of ISO-8859-1 so as to make it trivial to convert existing western text. Many essentially identical characters were encoded multiple times at different code points to preserve distinctions used by legacy encodings and therefore, allow conversion from those encodings to Unicode (and back) without losing any information. For example, the "fullwidth forms" section of code points encompasses a full Latin alphabet that is separate from the main Latin alphabet section because in Chinese, Japanese, and Korean (CJK) fonts, these Latin characters are rendered at the same width as CJK ideographs, rather than at half the width. For other examples, see Duplicate characters in Unicode.

What were the first 256 code points of Unicode made identical to?

Why were the first 256 code points made identical to ISO-8859-1?

to make it trivial to convert existing western text

What does the "fullwidth forms" section of code points encompass?

a full Latin alphabet that is separate from the main Latin alphabet

What are the CJK languages referenced?

Chinese, Japanese, and Korean

What did ISO-8859-1 copy?

I'm not sure.

Latin is what kind of language?

I'm not sure.

What are Latin characters called when they are half width?

I'm not sure.

Why do coders avoid duplicate characters?

I'm not sure.

The 256 initial points make it difficult to translate what kind of text?

I'm not sure.


In 1996, a surrogate character mechanism was implemented in Unicode 2.0, so that Unicode was no longer restricted to 16 bits. This increased the Unicode codespace to over a million code points, which allowed for the encoding of many historic scripts (e.g., Egyptian Hieroglyphs) and thousands of rarely used or obsolete characters that had not been anticipated as needing encoding. Among the characters not originally intended for Unicode are rarely used Kanji or Chinese characters, many of which are part of personal and place names, making them rarely used, but much more essential than envisioned in the original architecture of Unicode.

When was a surrogate character mechanism implemented in Unicode 2.0?

Why was a surrogate character mechanism implemented?

so that Unicode was no longer restricted to 16 bits

What are some characters not originally intended for Unicode?

rarely used Kanji or Chinese characters

Why are some foreign characters rarely used?

many of which are part of personal and place names

Why was the Unicode 2.0 codespace increased?

allowed for the encoding of many historic scripts

When was Unicode restricted to 16 bits?

I'm not sure.

What types of egyptian hieroglyphs are rarely used?

I'm not sure.

What are the extra Unicode characters called?

I'm not sure.

What types of characters were removed with Unicode 2.0?

I'm not sure.

What was removed in 1996?

I'm not sure.


Each code point has a single General Category property. The major categories are: Letter, Mark, Number, Punctuation, Symbol, Separator and Other. Within these categories, there are subdivisions. The General Category is not useful for every use, since legacy encodings have used multiple characteristics per single code point. E.g., U+000A <control-000A> Line feed (LF) in ASCII is both a control and a formatting separator; in Unicode the General Category is "Other, Control". Often, other properties must be used to specify the characteristics and behaviour of a code point. The possible General Categories are:

What are the General Categories of Unicode?

Letter, Mark, Number, Punctuation, Symbol, Separator and Other

What type of use is the General Category not helpful for?

not useful for every use, since legacy encodings have used multiple characteristics per single code point

What is the General Category in Unicode?

Other, Control

How many General Category properties does each code point have?

a single General Category property

What exists within the main Unicode categories?

subdivisions

What subcategories are found in the category Other?

I'm not sure.

Which category can always be used?

I'm not sure.

Why is Symbol not useful for all instances?

I'm not sure.

What is the title of the Separator category in Unicode?

I'm not sure.

"Other, Symbol" represents what unicode category?

I'm not sure.


Code points in the range U+D800–U+DBFF (1,024 code points) are known as high-surrogate code points, and code points in the range U+DC00–U+DFFF (1,024 code points) are known as low-surrogate code points. A high-surrogate code point (also known as a leading surrogate) followed by a low-surrogate code point (also known as a trailing surrogate) together form a surrogate pair used in UTF-16 to represent 1,048,576 code points outside BMP. High and low surrogate code points are not valid by themselves. Thus the range of code points that are available for use as characters is U+0000–U+D7FF and U+E000–U+10FFFF (1,112,064 code points). The value of these code points (i.e., excluding surrogates) is sometimes referred to as the character's scalar value.

What are code points in the range U+D800-U+DBFF known as?

high-surrogate code points

What are code points in the range U+DC00-U+DFFF known as?

low-surrogate code points

what is another name for a high-surrogate code point?

leading surrogate

what is another name for a low-surrogate code point?

trailing surrogate

What is known as a character's scalar value?

the range of code points that are available for use as characters

What is a low-surrogate followed by a high-surrogate called?

I'm not sure.

What is another name for a surrogate pair?

I'm not sure.

How many points are represented inside of BMP?

I'm not sure.

Which kinds of code points are valid by themselves?

I'm not sure.

What is the individual number of code points called?

I'm not sure.


The set of graphic and format characters defined by Unicode does not correspond directly to the repertoire of abstract characters that is representable under Unicode. Unicode encodes characters by associating an abstract character with a particular code point. However, not all abstract characters are encoded as a single Unicode character, and some abstract characters may be represented in Unicode by a sequence of two or more characters. For example, a Latin small letter "i" with an ogonek, a dot above, and an acute accent, which is required in Lithuanian, is represented by the character sequence U+012F, U+0307, U+0301. Unicode maintains a list of uniquely named character sequences for abstract characters that are not directly encoded in Unicode.

What is an ogonek?

a dot above

How does Unicode encode characters?

associating an abstract character with a particular code point

How are some abstract characters represented in Unicode?

a sequence of two or more characters

What is another name for an acute accent?

I'm not sure.

What does Latin require?

I'm not sure.

What are format characters associated with?

I'm not sure.

What do sets of graphic characters directly correspond to?

I'm not sure.

What are all encoded as singular unicode characters?

I'm not sure.


All graphic, format, and private use characters have a unique and immutable name by which they may be identified. This immutability has been guaranteed since Unicode version 2.0 by the Name Stability policy. In cases where the name is seriously defective and misleading, or has a serious typographical error, a formal alias may be defined, and applications are encouraged to use the formal alias in place of the official character name. For example, U+A015 ꀕ YI SYLLABLE WU has the formal alias yi syllable iteration mark, and U+FE18 ︘ PRESENTATION FORM FOR VERTICAL RIGHT WHITE LENTICULAR BRAKCET (sic) has the formal alias presentation form for vertical right white lenticular bracket.

What policy guaranteed that characters have a unique and immutable name?

Name Stability policy

What happens when a name is defective or misleading?

a formal alias may be defined

How long has this name immutability been guaranteed?

since Unicode version 2.0

What policy identified misleading characters?

I'm not sure.

When an error is found, what is used in place of a formal alias?

I'm not sure.

When was the formal alias yi created?

I'm not sure.

What is an example of a symbol that does not use a formal alias?

I'm not sure.

Which types of characters do not have unique names?

I'm not sure.


Unicode is developed in conjunction with the International Organization for Standardization and shares the character repertoire with ISO/IEC 10646: the Universal Character Set. Unicode and ISO/IEC 10646 function equivalently as character encodings, but The Unicode Standard contains much more information for implementers, covering—in depth—topics such as bitwise encoding, collation and rendering. The Unicode Standard enumerates a multitude of character properties, including those needed for supporting bidirectional text. The two standards do use slightly different terminology.

Who was Unicode developed in conjunction with?

International Organization for Standardization

What does Unicode share a character repertoire with?

the Universal Character Set

What includes topics like bitwise encoding, collation, and rendering?

The Unicode Standard

What do the two standards differ in?

slightly different terminology

Who created the character repertoire for IOS/IEC 10646?

I'm not sure.

What is another name for Unicode?

I'm not sure.

What is developed alongside the UCS?

I'm not sure.

Unicode has more information regarding what?

I'm not sure.

What have different character repertoires?

I'm not sure.


The Consortium first published The Unicode Standard (ISBN 0-321-18578-1) in 1991 and continues to develop standards based on that original work. The latest version of the standard, Unicode 8.0, was released in June 2015 and is available from the consortium's website. The last of the major versions (versions x.0) to be published in book form was Unicode 5.0 (ISBN 0-321-48091-0), but since Unicode 6.0 the full text of the standard is no longer being published in book form. In 2012, however, it was announced that only the core specification for Unicode version 6.1 would be made available as a 692-page print-on-demand paperback. Unlike the previous major version printings of the Standard, the print-on-demand core specification does not include any code charts or standard annexes, but the entire standard, including the core specification, will still remain freely available on the Unicode website.

When was the Unicode Standard first published?

When was the latest version, Unicode 8.0, released?

June 2015

What was the last major version of Unicode to be published in book form?

Unicode 5.0

What year was it announced that only the core specification for Unicode would be printed in physical form?

What does the print on demand, core version not include?

any code charts or standard annexes

When was the Consortium founded?

I'm not sure.

What month did the Consortium first publish Unicode?

I'm not sure.

When was it announced that Unicode would no longer be available in book form?

I'm not sure.

How many pages was the original Unicode standard?

I'm not sure.

What extra sections are not included on the Unicode website?

I'm not sure.


The Unicode Roadmap Committee (Michael Everson, Rick McGowan, and Ken Whistler) maintain the list of scripts that are candidates or potential candidates for encoding and their tentative code block assignments on the Unicode Roadmap page of the Unicode Consortium Web site. For some scripts on the Roadmap, such as Jurchen, Nü Shu, and Tangut, encoding proposals have been made and they are working their way through the approval process. For others scripts, such as Mayan and Rongorongo, no proposal has yet been made, and they await agreement on character repertoire and other details from the user communities involved.

Michael Everson, Rick McGowan, and Ken Whistler make up what group?

Unicode Roadmap Committee

What does the Unicode Roadmap Commmittee do?

maintain the list of scripts that are candidates or potential candidates for encoding

What proposal has been made for the Mayan script?

no proposal has yet been made

Where does the Unicode Roadmap Committee post information on these scripts?

Unicode Consortium Web site

Who are the potential candidates for encoding?

I'm not sure.

Who made the proposal for the Mayan script?

I'm not sure.

What needs to be agreed upon before a script for Jurchen is proposed?

I'm not sure.

Which scripts are user committees no longer proposing?

I'm not sure.

What committies have to approve proposals?

I'm not sure.


Unicode defines two mapping methods: the Unicode Transformation Format (UTF) encodings, and the Universal Coded Character Set (UCS) encodings. An encoding maps (possibly a subset of) the range of Unicode code points to sequences of values in some fixed-size range, termed code values. The numbers in the names of the encodings indicate the number of bits per code value (for UTF encodings) or the number of bytes per code value (for UCS encodings). UTF-8 and UTF-16 are probably the most commonly used encodings. UCS-2 is an obsolete subset of UTF-16; UCS-4 and UTF-32 are functionally equivalent.

How many mapping methods does Unicode define?

two

What are the two mapping methods that Unicode defines?

Unicode Transformation Format (UTF) encodings, and the Universal Coded Character Set (UCS) encodings

What do numbers in the names of the encodings indicate?

the number of bits per code value (for UTF encodings) or the number of bytes per code value

What are the most commonly used encodings?

UTF-8 and UTF-16

What does UCS stand for?

Universal Coded Character Set

How many mapping modes does USC have?

I'm not sure.

What maps an encoding?

I'm not sure.

What is the subset of UTF-8?

I'm not sure.

What is functionally equivalent to USC-2?

I'm not sure.

What do the sequences of values indicate?

I'm not sure.


The UCS-2 and UTF-16 encodings specify the Unicode Byte Order Mark (BOM) for use at the beginnings of text files, which may be used for byte ordering detection (or byte endianness detection). The BOM, code point U+FEFF has the important property of unambiguity on byte reorder, regardless of the Unicode encoding used; U+FFFE (the result of byte-swapping U+FEFF) does not equate to a legal character, and U+FEFF in other places, other than the beginning of text, conveys the zero-width non-break space (a character with no appearance and no effect other than preventing the formation of ligatures).

What does BOM stand for?

Unicode Byte Order Mark

What specifies the BOM?

UCS-2 and UTF-16

what is the code point of the BOM?

U+FEFF

What is U+UFFE the result of?

byte-swapping U+FEFF

What is the code point for BOM?

I'm not sure.

What changes the important property in BOM?

I'm not sure.

U+FFFE is equated to what?

I'm not sure.

What are UCS-2 and UTF-16 specified by?

I'm not sure.

What is the abbreviation for UCS-2 and UTF-16?

I'm not sure.


The same character converted to UTF-8 becomes the byte sequence EF BB BF. The Unicode Standard allows that the BOM "can serve as signature for UTF-8 encoded text where the character set is unmarked". Some software developers have adopted it for other encodings, including UTF-8, in an attempt to distinguish UTF-8 from local 8-bit code pages. However RFC 3629, the UTF-8 standard, recommends that byte order marks be forbidden in protocols using UTF-8, but discusses the cases where this may not be possible. In addition, the large restriction on possible patterns in UTF-8 (for instance there cannot be any lone bytes with the high bit set) means that it should be possible to distinguish UTF-8 from other character encodings without relying on the BOM.

What is the UTF-8 standard?

RFC 3629

Byte order marks are forbidden in protocols using what standard?

Why is it possible to distinguish UTF-8 from other protocols?

the large restriction on possible patterns

BOM can not replace what kind of UTF-8 text?

I'm not sure.

What is used to distinguish local 8-bit code pages?

I'm not sure.

What is the name of the BOM standard?

I'm not sure.

What type of bytes are required in a high bit set?

I'm not sure.

What type of patterns are rarely resticted?

I'm not sure.