IO Memory Map

Hex memory address

x x x x x
| | | | |
| | | | +------    1 (optional)
| | | |
| | | +--------   16
| | +----------  256
| +------------  4 k
+-------------- 64 k

So A000 is 640 kB

Addresses shared memory IO cards

These are classic addresses.

AddrDevice
A000 - AFFFMCGA
A000 - AFFFEGA
A000 - BFFFExtended EGA
A000 - BFFFVGA
B000 - B0FFMono
B000 - BFFFHercules
B800 - BBFFCGA
C000 - C7FFMCGA Rom
C000 - C7FFVGA Rom