Classic Computer Magazine Archive ANTIC VOL. 2, NO. 10 / JANUARY 1984


The Centronics connection


Managing Editor

To connect your Atari computer to a printer, you will need a cable. If the printer is an Atari printer, the cable will be supplied. A few other printers may also provide a ready-made cable, or make one available at extra cost (Alphacom, for example).

An acceptable alternative is to build your own cable. This is not as hard as it sounds, and can save you a little money.

You will need three items and some tools. The items include a 36-pin plug that plugs into the printer, a 15-inch plug that goes into the 850 Interface, and some cable. These can be obtained in any electronics hobby store.

The 36-pin plug you need is standard part number 57-20360. Do not get the similiar ICN-365, which, while easier to use, precludes connecting the wires in the desired order.

The 15-pin plug is commonly called a DA-15-p. Do not get the DA-15-S, which is the socket counterpart.

You will also need about five or six feet of multicolored ribbon cable, with a minimum of12 individually-insulated wires. Extra wires are okay, but these should be clipped so that they do not accidentally short any of the active wires or surfaces. Each wire in the cable has a distinctive color so that you can positively identify the same wire at each end.

Note that the connectors have a trapezoidal shape that prevents incorrect connection. The DA-1S-P is arranged this as you face it:


The Atari uses thes pins as follows:
Pin 1 is the Data Strobe
Pin 2 is data bit 0
Pin 3 is data bit 1
Pin 4 is data bit 2
Pin 5 is data bit 3
Pin 6 is data bit 4
Pin 7 is data bit 5
Pin 8 is data bit 6
Pin 9 is not used
Pin 10 is not used
Pin 11 is Signal Ground
Pin 12 is Fault
Pin 13 is Busy
Pin 14 is not used
Pin 15 is data bit 7

Note: data bits are sometimes numbered 1 through 8 in printer manuals.

As you can see, only 12 of the 15 pins are used. At the other end of the cable only 12 of the 36 pins of the 57-20360 plug are used. These pins are arranged this way as you face the connectors:


Connect these pins to the corresponding pins on the other end of the cable:

Pin 1 to the Data Strobe
Pin 2 to data bit 0
Pin 3 to data bit 1
Pin 4 to data bit 2
Pin 5 to data bit 3
Pin 6 to data bit 4
Pin 7 to data bit 5
Pin 8 to data bit 6
Pin 9 to data bit 7
Pin 10 is not used
Pin 11 to Busy
Pin 12-15 not used
Pin 16 to Signal Ground
Pin 17-31 not used
Pin 32 to Fault
Pin 33-36 not used

We have successfully used a cable like this to connect the Atari 850 Interface with the following printers: Epson FX100; Gemini 10X; Mannesmann Tally Spirit; NEC PC-8023A; Smith Corona TP1; and Transtar 120. If you have a printer other than these that accepts a 57-20360 plug, verify these connections in the "pin assignment" section of your owner's manual. Chances are that they will be the same, or can be easily modified.