[vcf-midatlantic] A few workshop notes

Herb Johnson hjohnson at retrotechnology.info
Mon Apr 30 10:57:34 EDT 2018

I was able to come out to the workshop on Sunday, and work on an unusual 
computer I obtained. It's a Motorola EXORset 30. It's a 6809 development 
system running an XDOS OS on floppy,  and supported by  Motorola's 
EXORbus bussed backplane. It came up without a lot of fuss. It needed 
some careful AC power conditioning to the power electrolytics.


I gave some support to Adam, who was able to operate his SGI Indigo 
computer for the first time, thanks to a keyboard and mouse I provided. 
I chatted with several people attending, providing sage wisdom about 
problems with RAM, switching speeds of diodes, pressure rollers on tape 
drives. I removed some rust from a couple of dot-matrix printers, and 
was surprised to find they could still print!

Thanks to Jeff Galinat, who leant me AC cables and a 360K diskette; and 
to Jeff Brace for his support of and at the Workshop.

Of course, I learned a lot about how my friends were diagnosing these 
issues. The depth of talent on site Sunday was amazing. It's rare and 
informative, to discuss 3-volt negative logic and the switching speeds 
of diodes at one point, then the problems of aged hard-rubber rollers at 
the next moment. I learned more about the early history of Apple II 
products. I got under the hood of some early Commodore PET's to see the 
less-than-industrial designs they produced early on. Any of these repair 
and preparation activities could be discussed at length.

And it's a pleasure to see what the Museum's UNIVAC is able to do, even 
as more work is in progress. To think that other shipboard computers 
like that, were operating at sea in the late 1970's is astounding. Then 
to have one operational today, that's a great gift. That's also true of 
the PDP-8 "straight-eight", which was under repair at the diode level 
this weekend. And it's good to see my friends again, see and hear about 
them and their work and history with vintage computing. Even the weather 
was cooperative.


Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net

More information about the vcf-midatlantic mailing list