ROM Memory Expansion and Control

C000:0000 - C000:7FFF ROM memory expansion area

C000:8000 - C000:CFFF XT HD-BIOS extension

- C800:0005 entry to physical format

C000:D000 - E000:FFFF ROM memory exp.-area (scanned)

System ROM

F000:0000 - F000:5FFF ROM memory exp.-area (scanned)

F000:6000 - F000:DFFF ROM BASIC

ROM BIOS (full IBM compatibles only!)

F000:E000 - F000:E6F1 Power-On Start-Up Test (POST)

F000:E6F2 - F000:E728 Bootstrap loader (INT 19H)

F000:E729 - F000:E82D RS23 I/O (INT 14H)

F000:E82E - F000:E881 Keyboard I/O (INT 16H)

F000:E882 - F000:E986 Keyboard scan code tables

F000:E987 - F000:EC58 Keyboard (INT 9H)

F000:EC59 - F000:EFD1 Disk I/O (INT 13H)

F000:EFD2 - F000:F044 Printer I/O (INT 17H)

F000:F045 - F000:F840 Video I/O (INT 10H)

F000:F841 - F000:F84C Memory check (INT 12H)

F000:F84D - F000:F858 Equipment check (INT 11H)

F000:F859 - F000:FA6D Casette I/O not used in XT

F000:FA6E - F000:FE6D Graphics character table

F000:FE6E - F000:FEF2 Time of day (INT 1AH)

F000:FEF3 - F000:FF52 Interrupt vector table

F000:FF53 - F000:FF53 Dummy return point for unused int.

F000:FF54 - F000:FFD9 Print screen (INT 5H)

F000:FFF0 - F000:FFF4 First code executed after power-on

F000:FFF5 - F000:FFFC BIOS release date