Employed in: C64, C128, CBM 8000 series
This port was once used for the datassette. Nowadays it is used only by some extensions like printer interfaces for a supply voltage. Note that the SX64 has NO cassette port.
ASCII version:
1 2 3 4 5 6
+--===-===+===-===-===-===--+
| | |
+--===-===+===-===-===-===--+
A B C D E F
Pin | Signal | Comment
-----+----------------+-------------
A-1 | GND |
B-2 | +5V |
C-3 | CASSETTE MOTOR | C64: controlled by P5 of CPU, P5=LOW -> 6V, P5=HIGH -> 0V
D-4 | CASSETTE READ | C64: connects with SRQ of IEC bus to /FLAG of CIA #1 via 3k3 pull-up resistor
E-5 | CASSETTE WRITE | C64: connects to P3 of CPU. Normally, this is an output.
F-6 | CASSETTE SENSE | C64: connects to P4 of CPU via 3k3 pull-up resitor. Normally, this is an input which reports a pressed key on the datassette by going LOW.
Note that cassette port #1 is J3 on the 8296, and #2 is J6.
Note: All pictures show the plug side.