Asus PCI-SC896 User Manual page 32

4. Appendix
Parity Checking - A way to verify the accuracy of data transmitted over the
SCSI bus. One bit in the transfer is used to make the sum of all the 1 bits either
odd or even (for odd or even parity). If the sum is not correct, an error message
appears.
PCI - Peripheral Component Interconnect. A local bus specification that al-
lows connection of peripherals directly to computer memory. It bypasses the
slower ISA and EISA busses.
Peripheral Devices - A piece of hardware (such as a video monitor, disk drive,
printer, or CD-ROM) used with a computer and under the computer's control.
SCSI peripherals are controlled through a SCSI host adapter.
Pin-1 Orientation - The alignment of pin-1 on a SCSI cable connector and the
pin-1 position on the SCSI connector into which it is inserted. External SCSI
cables are always keyed to insure proper alignment, but internal SCSI ribbon
cables are sometimes not.
PIO - Programmed Input/Output. A way the CPU can transfer data to and from
memory via the computer's I/O ports. PIO is usually faster than DMA, but
requires CPU time.
Port Address - Also Port Number. The address through which commands are
sent to a host adapter board. This address is assigned by the PCI bus.
Port Number - See Port Address.
Queue Tags - A way to keep track of multiple commands that allows for in-
creased throughput on the SCSI bus.
RAM - Random Access Memory. The computer's primary working memory
in which program instructions and data are stored and are accessible to the
CPU. Information can be written to and read from RAM. The contents of RAM
are lost when the computer is turned off.
RISC Core - ASUS SCSI chips contain a RISC (Reduced Instruction Set Com-
puter) processor, programmed through microcode scripts.
ROM - Read Only Memory. Memory from which information can be read but not
changed.The contents of ROM are not erased when the computer is turned off.
SCAM - SCSI Configured AutoMatically. A method to automatically allocate
SCSI IDs via software when SCAM compliant SCSI devices are attached.
SCSI - Small Computer System Interface. A specification for a high perfor-
mance peripheral bus and command set. The original standard is referred to as
SCSI-1.
32 ASUS PCI-SC896 User's Manual