VT52s, VT61s lots of DEC and DG keyboards- return trip through Maine, MA, NY, PA, OH, IN to IL

Jon Elson elson at pico-systems.com
Wed Oct 14 22:11:59 CDT 2015

On 10/14/2015 11:46 AM, tony duell wrote:
> [Versatec paper feed motors]
>> Yes, absolutely, on the Versatec 1200A.  I put those motors
>> in a milling machine.  Big, round case stepper motors, with
>> a ghastly resistor-transistor drive.
> You've got me worried now...
> I have  V80. Actually, it's ICL-badged, and has a GPIB adapter board at the back
> connected to the normal parallel port [1]. I was prepared to swear the motor in
> that is a normal DC motor, but perhaps I have misremembered it. I really don't
> want to strip it down tonight, and finding the manuals [2] Is an even bigger job.
Versatec made a lot of stuff, and went through a whole bunch 
of iterations.  But, a stepper seems MOST logical to advance 
the paper every time the line has been written.  A stepper 
is great to start and stop on a dime, and otherwise stay 
perfectly in synch with intermittent data from the 
computer.  The motor drive is inside the hinged top of the 
printer, but no telling if the V80 was built the same way.
> Yes, that's like the V80, but I am pretty sure on that machine the
> 'fountain' is on the suction side of the pump, that is it sucks from the outer
> region.
I can absolutely say the 1200A did not work that way, as you 
could manually start the fountain pump with the cover open.  
Now that I think about it more, I don't think you were 
supposed to be able to do that, but you could push a relay 
manually to do it.  Without the paper there, it could 
overflow if you let the pump run too long.
>   When there is paper present this causes toner to flow from the
> bottle up through the middle bit, then back round the outside to the pump
> and back to the bottle. Again I might be mis-remembering things...
That makes some sense, as it makes it pretty impossible to 
cause a spill.  But, it probably takes a lot longer to get 
the fountain started that way.
>> How could you do that???  Just the smell of the stuff should
>> have been adequate warning.
> Got any better ways to unclog the pump?
We never, ever had the pump clog.  Sometimes we needed to 
clean gunk out of the fountain area, but the pumps were 
never a problem.  The pump ran filled with the toner, and 
was below toner level in the bottle.  Sometimes if you 
hadn't printed in a while, the first page would come out 
partially blank, but then it would get going and work fine.  
Not sure if the V80 worked the same way, it sounds like 
maybe it was allowed to drip down and go dry when not 
printing.  That might have been the cause of the clogging.


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