Category : Tutorials + Patches
Archive   : TXTFILES.ZIP
Filename : MEMMINE.TXT

IBM XT (1 Megabyte) Memory Map with 64kb/Line
---------------------------------------------

This file contains an example filled in memory map template.
This represents the memory usage in an XT with the following
configuration and installed adapters which use memory:

- 640k of user memory on the motherboard (Type 2)
- IBM Token Ring Adapter II
- IBM Enhanced Graphics Adapter with maximum memory
- Future Domain TMC-830 SCSI Host adapter (Fixed Disk)
- Intel Above Board 286 with maximum memory

Bank 0, 256k (00000 to 3FFFF):
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
000000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
010000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
020000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
030000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù

Bank 1, 256k (40000 to 7FFFF):
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
040000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
050000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
060000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
070000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù

Bank 2, 64k (80000 to 8FFFF):
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
080000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù

Bank 3, 64k (90000 to 9FFFF):
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
090000: ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù

Video memory:
C = 128k of color graphics memory (EGA card)
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
0A0000: CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
0B0000: CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

Adapter board control memory:
M = 8k of ega card rom bios
T = used by IBM Token Ring Adapter II
F = 6k of Fixed disk bios (Future domain SCSI adapter)
E = 64k of LIM Expanded memory window
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
0C0000: MMMMMMMM........TTTTTTTTTTTTTTTTFFFFFF..........TTTTTTTT........
0D0000: EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

Motherboard ROM BIOS memory:
B = 32k of cassette basic
R = 8k of rom bios
: 0---1---2---3---4---5---6---7---8---9---A---B---C---D---E---F---
0E0000: ................................................................
0F0000: ........................BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBRRRRRRRR

Memory past this point is "extended memory" only possible in
286+ machines which have a Protected Mode. Machines using the
8086 or 8088 (like this XT) CANNOT access any memory beyond this
1 megabyte barrier.