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AP2500 Hardware Reference Guide
III. Appendix
III. Appendix
Peripherals
Peripherals are components on the outside of the computer such as a moni-
tor, printer, keyboard, or mouse. Peripherals are attached to the computer
via I/O ports. Peripheral devices allow your computer to perform an almost
limitless variety of specialized tasks.
POST (Power On Self Test)
When you turn on the computer, it will first run through the POST, a series
of software-controlled diagnostic tests. The POST checks system memory,
the motherboard circuitry, the display, the keyboard, the diskette drive, CPU,
and other I/O devices.
PS/2 Port
PS/2 ports are based on IBM’s Micro Channel Architecture. This type of
architecture transfers data through a 16-bit or 32-bit bus. A PS/2 mouse and/
or keyboard may be used on ATX motherboards.
RAID (Redundant Array of Inexpensive Disks)
RAID can be set up to provide mirroring (for fault tolerance), parity (for
data guarding), or striping (for data distribution over several drives for in-
creased performance). A RAID card is required to setup a RAID system.
RAM (Random Access Memory)
There are several different types of RAM such as DRAM (Dynamic RAM),
EDO DRAM (Extended Data Out DRAM), SDRAM (Synchronous DRAM).
ROM (Read Only Memory)
ROM is nonvolatile memory used to store permanent programs (called firm-
ware) used in certain computer components. Flash ROM (or EEPROM) can
be reprogrammed with new programs (or BIOS).
SCSI (Small Computer System Interface)
High speed parallel interface defined by the X3T9.2 committee of the Ameri-
can National Standards Institute (ANSI) for connecting many peripheral
devices.
UPS (Uninterruptible Power Supply)
A battery system that can provide power to an electronic device or com-
puter when power fails in the building. A passive UPS only provides power.
An active UPS provides power conditioning that offers protection against
transient power conditions and short-term power outages.
