PC AT Keyboard on C64
Keyboard Connector: (female - pin side view Not solder side)
        --v--
      /      \
     /        \
  3 Io      oI 1
     \ o   o / 
    5 \  o  / 4
        -----
          2 
Female KB-PORT (Solder side) C64 Datasette
1. KBD Clock     D,E--1     clock line (D is used as an interrupt source)
2. KBD Data       F--2     data line
3. N/C
4. GND       A--4
5. +5V (VCC)       B--5
REAR VIEW C64 CASETTE PORT
Solder side of Datasette cable
1 2 3 4 5 6
A B C D E F
PC-AT Port 4 5 n/c 1 1 2
GROUND +5V Motor Read Write Sense
1-A GROUND
2-B +5V
3-C MOTOR
4-D READ
5-E WRITE
6-F SENSE
VIEW PINS C64 DATASETTE CABLE CONNECTOR
6 5 4 3 2 1
F E D C B A