IBM 5150 - Block Diagram

Several keyboard arrangements are available. These are
illustrated on the following pages.
For information about the
keyboard routines required to implement non-U.S. keyboards,
refer to the
Guide to Operations and DOS manuals.
Block Diagram
8255A5 LS322
PAO-------lOH OH'
PA1 OG
PA2 OF
PA3 OE
PA4------I
PA5-------l
PA6------4
PA7------4
PB7
PB6
Keyboard
Clock
1
0
IRQ1
Keyboard
2
0
Data 3
0
Reset
4
0
GND
0
5
+5V
PC LK --'--I---l
Keyboard Interface Block Diagram
4-4 Keyboard