Parallel printer cable
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From: Brian.Strang@cereal.mv.com (Brian Strang)
Subject: Parallel printer cable
Date: Sat, 8 Mar 1997 10:38:00 GMT


I have the standard serial to parallel interfaces like, Cardco +G,
G-Whiz, some really old MW-302's and Super Graphix. Or are you looking
for the cable that comes off the user port like Geocable?

Here is an imported message from a friend on the Fido CBM echo who
occasionaly builds them...
This will allow you to use a standard printer cable from an IBM machine
to interface with his creation. If you want to make a stand alone cable
just use the pinouts in his message.


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Date : 02-15-97      Time : 10:41    Status : Public - Unread
From : Phil Heberer                  Subj   : Mps1000...
To   : Geir_eivind Mork              Area   : Cbm

Hello!

 GM> when you talk about printers, is it possible to connect a standard
 GM> printer to the c64 using some sort of hack/hardware ?

It's not really a hack to make up a parallel cable for the User Port
(modem port). There are quite a number of programs that support this
(GEOS gc drivers, SuperBase, SuperScript to name a few). This is what
*I* do.


I just recently had need to make up another geocable, but rather than
cut up another IBM style cable to put the CBM User Port connector on
it, I made up a geocable-compatible parallel port for the CBM using an
old 1660 300 baud modem case. I pulled the modem PCB out of the case,
and desoldered the User Port connector. I broke out the piece of the
case between the two telephone jacks, and did a little filing so a DB25
socket could fit neatly in the hole I made. The connections are:

User Port Pin   Function   DB25 Pin
     A          GND(Flag)  19-24 (interconnected, pick one)
     B          BUSY       11
     C          PB0         2
     D          PB1         3
     E          PB2         4
     F          PB3         5
     H          PB4         6
     J          PB5         7
     K          PB6         8
     L          PB7         9
     M          PA2(Strobe) 1
     N(Not Used)Auto-LF     14<->19

On this last part, I connected pin 14 via toggle switch to pin 19 on
the DB25, which allows me to toggle Auto-Linefeed on/off on the
printer. The toggle switch was installed in the hole left by the
Answer/Originate slide switch of the modem. I epoxied the User Port
connector and the DB25 to the top half of the case, and discarded the
modem PCB. The Radio Shack part # for the DB25 is 276-1548, and it
costs $1.99. This makes for a quite nice looking port on the Commodore,
and allows me to use a regular IBM style printer cable to either my
NS-1000 or BJC-610. It works quite well with Perfect Print LQ under
GEOS, and also works with the parallel printer patch for Fun Graphics
Machine and TWS128. Anyone with minimal soldering skills should be able
to do this, BTW. You just need to be careful that the User Port
connector is installed correctly, and NOT upside down! (Pins A-N are on
the BOTTOM side of the User Port as you look at it, with A on the
bottom left).

If you have most of the parts laying about, as *I* did, this is a cheap
project. If you need to buy the parts, printer cables can be found for
around $4.95 at most office supply stores, and 300 baud CBM modems can
often be found at flea markets, thrift stores, pawn shops, etc. I have
even offered $5 for 300 baud CBM modems in local freebie newspapers,
and have had several given to me by Amiga users in my local user group.
A worst-case scenario would be about $12-15 for a multi-purpose
geocable! <grin> The end result looks quite "professional" with a bit
of care, and you *might* even luck out and find one of the modem cases
that match the color of the C64c or C-128!

Cheers,
Phil

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