New batch of pdp8 OMNIBUS to USB interface! Please Read and react!

Tony Duell ard.p850ug1 at
Thu Feb 16 10:17:27 CST 2017

On Thu, Feb 16, 2017 at 1:59 PM, Paul Koning <paulkoning at> wrote:
> The LA36 was an excellent machine.  Unlike the LA30, with its atrocious keyboard
> and a print mechanism that jammed about every 20th carriage return.

I have to disagree with that. The LA36 is horrible. There is a major
design misfeature.

There is no separate home sensor. Instead the carriage is run into the
left end-stop,
the motor stalls, and the logic detects this by a lack of pulses from
the rotary encoder
on the motor spindle. Now, if the (weak, plastic) key in the carriage
belt sprocket
breaks, the motor doesn't stall. It keeps turning, slowly, with the
spindle slipping
in the sprocket. The logic sees encoder pulses and keeps it turning.
But the load
is excessive for the motor, which generally gets hot enough to burn
the enamel off
the windings.

Do NOT ask how I found this out. Suffice it to say a friend and I had
to rewind the motor
in an LA36 at the university we were studying at.


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