ph274cc@prism.gatech.EDU (Charles Cleveland) (04/12/91)
This falls in the category of things I ought to remember but don't. Most of my life falls in that category. I think my 1000's printer cable has been trashed --- at least the printer didn't print the last time I reconnected it and I found my desk sitting on top of the cable. I want to get another cable quickly, but can't remember whether a readily-available, IBMPC-type cable is compatible or not, or what pinout adjustments (or, as I write this, even gender changes) may be needed. My recollection is that the 1000's parallel connections are PC compatible while the serial ones are not. But if I had any real confidence in my recollections I wouldn't be posting this. Thanks.
amatthews@zodiac.rutgers.edu (04/14/91)
As far as I know, you cannot use a standard generic IBM type parallel port connector to connect a printer to the 1000. I tried this with my new Citizen GSX 140, and every line had an extra line feed in it, even when the computer was off. As soon as I disconnected the cable, the extra LF's went away. I called the place I ordered the printer from, and they told me that they did have a cable for sale for the 1000 with a little note attached saying it was for the 1000 ONLY. I purchased the cable and now everything is working just fine.
rzv30@cccvm.ccc.amdahl.com (Rene' A. Vega) (04/17/91)
The Amiga 1000 parallel port is NOT PC compatible. You'll discover this if you
try to plug in an off the shelf Centronics to db25 cable. First off, the Amiga
parallel port is a male connector instead of female. Secondly, if you interpose
a female to female gender changer then plug in a standard printer cable, you'll
short out the +5v that's on pin 23, plunging your A1000 into a power supply
screaming abyss.
You see, the A1000 parallel port isn't quite centronics compatible. Pins 1-13
map properly, but 14-25 do not. Here's the map:
Amiga side Real world
------------ --------------
14 GND 14 AutoFormFeed* (to ptr)
15 GND 15 Error* (to cpu)
16 GND 16 Initialize* (to ptr)
17 GND 17 Select in (to ptr)
18 - 22 GND 18-22 GND
23 +5V 23 GND
24 n/c 24 GND
25 Reset* 25 GND
I recently had to remake an A1000 cable since my old one kinda fell apart.
Turns out my cat thought it was a great teething toy for the last few months.
Anyway, I bought a short female to male DB25 cable (they seem to be the least
expensive of the bunch), cut off the male end, bought a female DB25 connector
and housing then soldered the wires thus:
Amiga side Printer side
------------- --------------
1 - 13 1 - 13
14 (n/c) 14 (n/c)
15 (n/c) 15 (n/c)
16 (n/c) 16 (n/c)
17 17
18 - 22 18 - 22
23 (n/c)!! 23 (connect to 22)
24 (n/c) 24 (connect to 22)
25 (n/c) 25 (connect to 22)
This arangement works with my HP LaserJet directly as well as a two-way
electronic switch (it's called laser access).
Have fun!
Rene' A. Vega
Computer & Systems Architecture