Project: Parallel cable for printing with 'Centronics' printers.
Target : C64, C128, SX64
Time : 30 min.
Cost : <10 US$
Use : Print to Centronics printers without expensive interface.
Cable which connects to the C-64's user port and to the centronics
jack of a printer.
Programs supporting printing are usually designed for printers
connected to the serial port. But very many of them also support
centronics printers (the ones for your PC) connected to the userport. For
these programs (also many Speeders support centronics printers)
you need the circuitry below.
For the same reason described in 'C128D keyboard for C-64' the
user port must not be connected directly to the cable.
- 2-5m 11-core ribbon cable
- 1 user port connector
- 1 25-pin SUB-D connector (female) OR
- 1 36-pin centronics connector (male)
- Build the following circuit on a Vector board; if you can get
it, take one designed for the userport (with 12 solder pads
in a 3.96mm raster)
The simple version (which requires no extra chips) is in the table
below the picture.
User port | 25-pin SUB-D | 36-pin centronics | Signal
A (GND) | 18-25 | 19-30 | GND
B (Flag2) | 10 | 10 | /ACK
C (D0) | 2 | 2 | Data 0
D (D1) | 3 | 3 | Data 1
E (D2) | 4 | 4 | Data 2
F (D3) | 5 | 5 | Data 3
H (D4) | 6 | 6 | Data 4
J (D5) | 7 | 7 | Data 5
K (D6) | 8 | 8 | Data 6
L (D7) | 9 | 9 | Data 9
M (PA2) | 1 | 1 | /Strobe
- Do not forget to connect pin 7 of the
7407 to GND and pin 14 to +5V.
- Pin 1, 10 and 19 of the 74HC541 must be connected to GND, pin 20
- For the electrolytic capacitor best use a 4.7uF tantal
type, the exact value is not critical, it is only for
- For the LEDs best use a high-efficiency types, i.e. those with
2mA current consumption, else the 1.5k resistor must be 150ohms
for normal LEDs.
- The 7407 pins 1, 3, 5, 9, 11 and 13 are inputs and the pins 2, 4,
6, 8, 10 and 12 are outputs! You need only 4 of the 6 drivers in
- Connect the userport pins with the circuit according to the
table above, on the other side of the circuit, connect either
a 25-pin D-Sub plug (female, for use with standard centronics
printer cables) or a 36-pin centronics plug (male).
- Soldering errors, did you read the notes?
Updated: January 7th, 1998
Created: February 11th, 1997
Status : NOT VERIFIED!
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!