Technical Reference
41
Table 10 lists the system memory map.
Table 10. System Memory Map
Address Range
(decimal)
Address Range
(hex)
Size
Description
1024 K - 8388608 K
100000 - 1FFFFFFFF
8191 MB
Extended memory
960 K - 1024 K
F0000 - FFFFF
64 KB
Runtime BIOS
896 K - 960 K
E0000 - EFFFF
64 KB
Reserved
800 K - 896 K
C8000 - DFFFF
96 KB
Potential available high DOS
memory (open to the PCI bus).
Dependent on video adapter used.
640 K - 800 K
A0000 - C7FFF
160 KB
Video memory and BIOS
639 K - 640 K
9FC00 - 9FFFF
1 KB
Extended BIOS data (movable by
memory manager software)
512 K - 639 K
80000 - 9FBFF
127 KB
Extended conventional memory
0 K - 512 K
00000 - 7FFFF
512 KB
Conventional memory
2.2
Connectors and Headers
CAUTION
Only the following connectors and headers have overcurrent protection: Back panel
and front panel USB.
The other internal connectors/headers are not overcurrent protected and should
connect only to devices inside the computer’s chassis, such as fans and internal
peripherals. Do not use these connectors/headers to power devices external to the
computer’s chassis. A fault in the load presented by the external devices could cause
damage to the computer, the power cable, and the external devices themselves.
NOTE
Computer systems that have an unshielded cable attached to a USB port may not
meet FCC Class B requirements, even if no device is attached to the cable. Use
shielded cable that meets the requirements for full-speed devices.
This section describes the board’s connectors and headers. The connectors and
headers can be divided into these groups:
•
Back panel I/O connectors (see page 42)
•
Component-side connectors and headers (see page 43)