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Posted By

Sigmoid
on 2016-08-11
10:06:58
 Commodore 16 hardware eval and reconditioning

Hey. happy

I got a c16 recently. It was stored indoors and seems free from rust or damage, the keyboard and the casing is quite pristine, as was the paper shielding (that I removed first chance I got, no need to add insult to injury on the thermal front).

Anyway, it seems someone has done a few things to it. First of all, someone has apparently plugged a power supply in backwards, as the fuse had been replaced by a piece of wire. (I'll have to get a new fuse, I don't like this...)

Also, there are a number of bodged-on diodes. I took photos, will include links in a moment... I have heard that there was a hack with diodes you had to do on RevA c16 boards to enable external 64k RAM expansions, but I've never seen it actually described - if someone could post a link, I could compare...

As for functional state of the machine, at a first look via a monitor cable, video seems good, the keyboard works. One worrying thing I found is that when I play sound from BASIC (vol 8;sound 1,516,100) on either channel, the sound does play, but I get this intermittent glitching a few times a second, almost as if the computer would repeatedly stop playing the sound for an interrupt or something, and then resume.

I don't remember this from my Plus4, and the VICE emulator doesn't do it either, so I'm thinking it's something problematic - something is fed somewhere it shouldn't be. Anyone familiar with this issue?

Posted By

Sigmoid
on 2016-08-11
10:26:30
 Re: Commodore 16 hardware eval and reconditioning

So here are the photos...
https://drive.google.com/open?id=0B5axzxOcJ-5IdmNOZHhmSGZ6QTQ

IMG_0002: See the "flying" diode above U8.

IMG_0003: What's with those two diodes with the shrinkwrap?

IMG_0004: That bodged-on parallel diode in the diode row next to the Datasette connector...

IMG_0005: And finally, as dessert... *bleep* this guy, was a new fuse really this expensive?

Also, it seems the electrolytic capacitors have different footprints than the board was made for. I wonder if this means they are new or that the factory just used what they had on hand...



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