> From: James Meagher
>
> I have acquired Polaris SN 300030 in a state of limited
> functionality (it makes noise, but that's about it), and am
> wondering if I should look out for anything specific with
> such an early SN while I have it open and am replacing the
> membrane panels, batteries, and giving it a good clean?

Reseat connectors, and perhaps even socketed chips. Measure power supply
voltages (and check for ripple if you have access to a scope). Do all
calibrations. Take apart the keyboard and clean the boards and the insides
of the dome switches. If you have access to an EPROM programmer, reprogram
the EPROMs to make sure they're not fading or have old buggy code.

> Also, I am interested in replacing all the LEDs with white or
> blue ones, but am having difficulty finding a suitable
> replacement in those colours that won't be blindingly bright
> in a dimly lit room (made that mistake with my last Polaris
> refurb). Curious if anyone has any ideas on this?

The LEDs are driven directly off LS-TTL shift registers, with no
resistors. This is the absolute cheapest way to drive LEDs, but you can't
really know how bright a particular LED will be without trying it. You'll
just have to buy one of each LED that you can find in that package, and
try them out.

> P.S. Did anything ever come of the redesigned output board
> that was once being talked about?

No. However, I'll be doing a small production run of my Digital Chroma
boards in the next couple of months, and I'll bug my friend to include his
little board in the order. He's just been busy with other stuff.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...