Memory Map; System Memory Map - NEC POWERMATE PROFESSIONAL 9000 Service Manual

1-14 Technical Information
NEC's Flash ROM allows fast, economical BIOS upgrades. The Flash ROM is a
reprogrammable EPROM containing both the system and video BIOS. Using the Flash
ROM to change the ROM BIOS provides the following advantages:
T
the BIOS upgrade is performed quickly and easily
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the expense of replacing ROM BIOS chips is eliminated, so system maintenance
costs are reduced
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there is less chance of inadvertently damaging the system board than when
physically replacing ROMs
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new technology can be incorporated while maintaining corporate standards
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network administrators can exercise company-wide control of BIOS revisions.
The BIOS programs execute the Power-On Self-Test, initialize processor controllers, and
interact with the display, diskette drives, hard disk drives, communication devices, and
peripherals. The system BIOS also contains the Setup utility. The POST copies the ROM
BIOS into RAM (shadowing) for maximum performance.
The Flash ROM allows the system and video BIOS to be upgraded with the BIOS Update
utility, without having to physically remove the ROM (see Section 2 for further information
on the BIOS Update utility). The Flash ROM supports the reprogramming of the system
BIOS and the video BIOS.

Memory Map

The system memory map is shown in Table 1-3.
Address Range
(Decimal)
1024 K - 1048576 K 100000 - 3FFFFFFF
1024 K - 524288 K
928 K - 1024 K
800 K - 928 K
640 K - 800 K
639 K - 640 K
512 K - 639 K
0 K - 512 K
Table 1-3 System Memory Map
Address Range (Hex) Size
100000 - 1FFFFFFF
E8000 - FFFFF
C8000 - E7FFF
A0000 - C7FFF
9FC00 - 9FFFF
80000 - 9FBFF
00000 - 7FFFF
Description
1023 MB Extended memory (EDO memory)
511 MB Extended memory (SDRAM)
96 KB System BIOS
128 KB Available high DOS memory (open
to ISA and PCI bus)
160 KB Video memory and BIOS
1 KB Extended BIOS data (movable by
memory manager software)
127 KB Extended conventional memory
512 KB Conventional memory