Zorba owners/Help diagnosing display issues

Ben McAllister ben at listenfaster.com
Tue Nov 2 17:22:07 CDT 2021

Hello from Seattle everyone,

I'm new to the list. I recently bought a Zorba on Ebay, which was my first
machine as a kid back in 1985, dialing into BBSs and learning assembly and
basic. I put a lot of hours in on this machine and was very excited to
acquire one, even though the sale was 'as is'.  I have some issues to
address, beginning with perhaps a faulty component on the video board
driving the crt.

While I'm an experienced programmer and have some rudimentary skills with
electronics, I'm going to be in bootcamp troubleshooting this board. I have
some help in my network of friends, but wanted to throw this out to the
list.  Are there any Zorba owners who would be willing to trade
notes/advice with me on their experiences troubleshooting hardware issues
(or anyone else out there, for that matter :) )?  Have you used the
composite video out to feed another monitor?

Detail on my first issue: the display appears to need the kind of
stabilization I _thought_ the horizontal and vertical hold adjustments
would provide, but it's not entirely stable. I have tried the composite
out, feeding it to a cheap composite->HDMI adapter, but that signal looks
like a blank screen in need of vert/horiz hold adjusting.  Before I go much
further, I was hoping someone out there might be able to verify their use
of the composite out to an external display. I haven't found any detail on
what that signal should look like, other than it's 'composite' - maybe
someone with more expertise can tell me what assumptions I can make about a
composite signal.

Thanks for reading that long message - and glad to be a new member of the

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