Section 4. Keyboard - IBM AT 5170 Technical Reference

SECTION 4. KEYBOARD
Contents
Description ................................... 4-3
Cabling ................................... 4-3
Sequencing Key Code Scanning ................. 4-3
Keyboard Buffer ............................ 4-3
Keys ...................................... 4-4
Power-On Routine ................••.••........... 4-4
Power-On Reset ............................ 4-4
Basic Assurance Test ......................... 4-4
Commands from the System ...•••••.••.....••.••••.•• 4-5
Reset (Hex FF) .........................•... 4..5
Resend (Hex FE) ............................ 4-6
No-Operation (NOP) (Hex FD through F7) ....... 4-6
Set Default (Hex F6) ......................... 4-6
Default Disable (Hex F5) ..................... 4-6
Enable (Hex F4) ............................ 4-6
Set Typematic Rate/Delay (Hex F3) ............ 4-7
No-Operation (NOP) (Hex F2 through EF) ....... 4-8
Echo (Hex EE) ............................. 4-8
Set/Reset Mode Indicators (Hex ED) ............ 4-8
Commands to the System .•••...........•............ 4-9
Resend (Hex FE) ............................ 4-9
ACK (Hex FA) ............................. 4-9
Overrun (Hex 00) ........•................. 4-10
Diagnostic Failure (Hex FD) .................. 4-10
Break Code Prefix (Hex FO) .................. 4-10
BAT Completion Code (Hex AA) .............. 4-10
ECHO Response (Hex EE) ................... 4-10
Keyboard Scan-Code Outputs ...•....•.•.......•..•• 4-11
Keyboard 4-1