Datasheet

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Chapter 1
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Personal Computer System Components
The 40-pin ATA header transfers data between the drive and motherboard multiple bits
in parallel, hence the name Parallel ATA. SATA, in comparison, which came out later and
prompted the retroactive PATA moniker, transfers data in serial, allowing a higher data
throughput because there is no need for more advanced parallel synchronization of data sig-
nals. The SATA headers are vastly different from the PATA headers. Figure 1.16 shows an
example of the SATA data connector.
FIGURE 1.16 The Serial ATA connector
Keyboard Connectors
The most important input device for a PC is the keyboard. All PC motherboards contain a
connector that allows a keyboard to be connected directly to the motherboard through the
case. There are two main types of wired keyboard connectors. Once, these were the AT and
PS/2 connectors. Today, the PS/2-style connector remains popular, but it is quickly being
replaced by USB-attached keyboards. The all-but-extinct original AT connector is round,
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