Usings a Jamma Power supply for a Trs-80 Model 1????

[dabone]

I've got an untested Trs-80 here, with no power supply, but I do have a couple of Jamma power supplies laying around.

The Jamma specs provides +12, +5 and -5 , (4a/16a/1a) on the supply I have handy.

Has anyone ever used one to power a Model 1?

Thanks.

 

[Eudimorphodon]

The Model I takes unregulated power at two voltages, nominally around 14 volts AC and 19 volts DC. (Although we’re using the term “DC” loosely here, it’s just AC pumped through some diodes.) All the regulation of those feeds into +12v and +/-5v is on the computer’s main board.

So long and short of it, to power it with a regulated supply you’ll need to bypass the main board’s regulator goo and direct feed it on the south side of it. That’s probably not too difficult in principle, the technical manual has all the gritty details, but you’ll need to snip some components or cut traces.