ODEC/ Data 100/ LC8-P (M8365) PDP8 printer interface schematics
elson at pico-systems.com
Tue Jan 31 11:14:19 CST 2017
On 01/31/2017 06:45 AM, David Gesswein wrote:
> On Sun, Jan 29, 2017 at 10:27:49PM -0600, Jon Elson wrote:
>> I think we had an Odec chain printer that another group gave us to
>> use on our VAX. I hacked it up to shut off the chain motor when it
>> wasn't printing, and then restart it when print data came in.
> Mine has a switch to select that and control codes to turn it off and on.
I seem to remember it turned out VERY easy to do this. I'm
guessing my unit had control codes, but we didn't want to
hack the VAX software, so I rigged a one-shot to do it instead.
> Mine has the same path. The manual has a procedure for adjusting the guides
> for ribbon foldover problems. It came with multistrike film ribbons so
> hopefully they won't be a pain. Looks like they used 35mm film reels for
> the ribbon. Were you using normal inked cloth?
Yes, inked cloth ribbons. They were cheap, but ran properly
for a short time before they started skewing. You could
either replace the ribbon after 1/10th of the print life was
exhausted or keep fiddling with the tracking to try to get
to 50% usage.
At home I had a HUGE Honeywell 300 LPM drum printer with a
weird character set and a totally nonstandard interface.
it also used a folded ribbon scheme, with 2" wide ribbons.
That one NEVER had ribbon tracking issues, you could run the
ribbon until you could see through it, and it still tracked
fine. I never knew WHY the tracking on the Odec was so
finicky. Possibly just we were using crummy ribbons that
were not made with the right cloth. I don't think we ever
bought ribbons for it, the people who gave it to us gave us
a box of new ribbons.
> Good to know its a nice
> printer otherwise. Pretty slow for a chain printer, only 125 LPM. Haven't
> figured out if its a real difference or board jumpers between it and the
> 1423 200 LPM.
OK, ours was also slow, but it had lower and upper case. I
suspect a different chain with upper case only would print
twice as fast.
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