IBM 5150 - Section 5. System Bios

SECTION 5. SYSTEM BIOS
Contents
System BIOS Usage ...•.........•.........•....•.. 5-3
Vectors with Special Meanings ................. 5-6
Other Read/Write Memory Usage .............. 5-8
BIOS Programming Hints
.................... 5-13
Adapter Cards with System-Accessible
ROM
Modules ......................... '. . . . . . . .. 5-13
Keyboard Encoding and Usage
....................... 5-14
Encoding ................................. 5-14
Extended Codes
............................ 5-18
Shift States
................................ 5-19
Special Handling
........................... 5-20
Extended Functions
......................... 5-21
~ Keyboard Usage ........................... 5-22
BIOS Cassette Logic .............................. 5-25
Software Algorithms - Interrupt Hex 15 ......... 5-25
Cassette Write
............................. 5-25
Cassette Read
............................. 5-26
Data Record Architecture .................... 5-27
Error Recovery
............................ 5-28
System
BIOS Listing
5-29
Quick Reference
5-29
System BIOS
5-1