Microvax II 'primer'?

Jules Richardson jules.richardson99 at gmail.com
Tue Jan 23 21:12:00 CST 2018

On 01/22/2018 08:07 AM, Adrian Graham via cctalk wrote:
>> At this stage I've got no idea if it's a SMPSU or a linear (I've not
> popped the panel off)... I suppose if it's linear then it perhaps doesn't
> even need a load to do its thing. If it's a switcher then I expect it'll at
> least need something on +5V, and maybe +12V too (unless it has built-in
> load resistors to keep the regulation happy, as designs occasionally do).
> It's actually 3 separate boards and 2 identical discrete PSUs for +12 and
> +5 in a massive metal box, the thing is a beast and fits along the whole
> side of the machine behind the Q22 backplane.

Aha, so it is... I just removed it for a visual inspection. Pretty clean 
inside, some dust, five or six mouse turds (but no sign of piss damage), a 
chunk of slate, and a golf tee.

When the bit of slate fell out I was a little concerned that it was a 
fragment of ceramic IC/component packaging, but I really do think it's just 
a piece of slate tile or whatnot that had somehow found its way in there 
over the years.

No obviously-roached caps or other components, so I'll figure out some form 
of loading and give it a go.



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