C.2 1st MB memory map
Table C.2: 1st MB memory map
Addr. range (Hex) | Device |
|
|
F0000h - FFFFFh | System ROM |
*CC000h - EFFFFh | Unused (reserved for Ethernet ROM) |
C0000h - CBFFFh | Expansion ROM (for VGA BIOS) |
B8000h - BFFFFh | CGA/EGA/VGA text |
B0000h - B7FFFh | Unused |
A0000h - AFFFFh | EGA/VGA graphics |
00000h - 9FFFFh | Base memory |
*If Ethernet boot ROM is disabled (Ethernet ROM occupies about 16 KB)
*E0000 - EFFFF is reserved for BIOS POST
C.3 DMA channel assignments
Table C.3: DMA channel assignments
Channel Function
0Available
1Available (audio)
2Floppy disk
3Available (parallel port)
4Cascade for DMA controller 1
5Available
6Available
7Available
*Audio DMA select 1, 3, or 5
**Parallel port DMA select 1 (LPT2) or 3 (LPT1)
89 | ChapterC |
