Specifications

Glossary
G-11
Serial Port: A physical connection with a computer for the purpose of serial data
exchange with a peripheral device. The port requires an I/O address, a
dedicated IRQ line, and a name to identify the physical connection and
establish serial communication between the computer and a connected
hardware device. A serial port is often referred to as a COM port.
Shadow Memory: RAM in the address range 0xC000h through 0xFFFFFh used for
shadowing. Shadowing is the process of copying BIOS extensions from
ROM into DRAM for the purpose of faster CPU access to the extensions
when the system requires frequent BIOS calls. Typically, system and video
BIOS extensions are shadowed in DRAM to increase system performance.
Single In-Line Memory Module (SIMM): A small, rectangular circuit board on
which is mounted semiconductor memory ICs.
Small Outline Dual Inline Memory Module (SO DIMM): A new form factor for
memory modules that is smaller and denser than SIMMs.
Standoff: A mechanical device, typically constructed of an electrically non-
conductive material, used to fasten a circuit board to the bottom, top, or side
of a protective enclosure.
Static Random Access Memory (SRAM): A semiconductor RAM device in which
the data will remain permanently stored as long as power is applied, without
the need for periodically rewriting the data into memory.
Symmetrically Addressable SIMM: A SIMM, the memory content of which is
configured as two independent banks. Each 16-bit wide bank contains an
equal number of rows and columns and is independently addressable by the
CPU via twin row address strobe registers in the DRAM controller.
SYSCLK: ISAbus System Clock. The ~8.33MHz clock signal present on the ISAbus
to which all bus transactions are synchronized.
System Memory: See Conventional Memory.
 T 
Terabyte (TB or TByte): Approximately one thousand billion (US) or one billion
(Great Britain) bytes. 2
40
= 1,099,511,627,776 bytes exactly.