Connectors | Data Communications
Standard Serial Communications | Universal Serial Bus

Serial communications

Standard Serial Communications

[Serial data movement]

Serial Data Communications is where a character is broken down into it's component binary digits and sent sequentially. (uses a UART chip)
This not as efficient as parallel data transfers.
Serial Data Communications can be used in conjunction with the Telephone system because VOICE Communication technology does not use parallel data paths.
This means that in conjunction with a telephone system, serial data communications can occur between an geographic locations that have telephones.

Technical details

hwdccon.jpg (8045 bytes)

Serial ports are built around a chip called a UART (Universal Asynchronous Reciever/Transmitter).
Early PCs used Uart models 8250 and 16450
Bandwidth: 150Kbps (0.15 Mbps)
Current PCs (1998)
- Use 16650 and 16750 required for ISDN connections

Universal serial bus (USB)

A serial bus enabling up to127 peripherals to be chained to a single connector instead of multiple ports.
Bandwidth: USB-1 = 12Mbps, USB-2 = 480Mbps
Specifications available on Internet http://www.teleport.com
Support for USB-1 introduced in Windows95 OSR2, USB-2 expected in 2002.
Expected to replace many of standard connectors, but has been slow to be
Two ports are included with most PCs manufactured from Jan 1998. Each port may have peripherals daisy chained.
Uses; keyboards, mice, scanners, digital audio systems, still & video cameras and joystick/game controllers.
Uses (USB-2) : Hard drives, CD-RW, video
Ref (1998,Jun) English,D, [140]Computerworld NZ Nov '95

Ref: Steers, K. (2001, Oct). Hardware tips, USB-2.0 or Firewire?. NZ PC World # 143, p 101
[Rev: 10/31/2001 ] 8/12/97 © 1997-01 V/2-Com (Verhaart), P O Box 8415, Havelock North, New Zealand.