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Cassette Port

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.

Connection scheme

Picture (ASCII version below)
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.

[1] Commodore User's Guide
[2] Hardware-Basteleien zum C64/C128, p.271, ISBN 3-89090-389-4
[3] CBM 8296, Nachtrag zum 8096 Handbuch, p.7

Updated: January 7th, 1998
Created: February 4th, 1997

Site copyright © 1997 by Marc-Jano Knopp
This document is part of MJK's Commodore 64 & LCD Page
Brought back to life by Peter Schepers, Dec 10, 2005 because I really liked this site!