SID

[Michael Buchstaller]

>When Andreas was talking about the sad chip the sid chipjust popped up to my mind...Anyone knows where to get it?

There are sooo many C64 out there that can be had for cheap. The power supplioes on them
do fail pretty often, and noone can get a replacement one, and repairing is impossible because
they are potted in epoxy. So people give away their old C64 for as low as 10...30 DM here,
(would be approx. 5...15 US$). Often less for phsically damaged units (missing keys, discolored
plastic)

I can always get them at flea markets. Also there are always C64s on Ebay, though a little pricier.

Beware: There are two versions of the SID chip: the (older) 6581 which needs 12 V, and the later
6582 (i have never seen a SID labeled "6582", all of mine are labelled "8580R5") that is supposed
to run on 9 V.

BTW: Question to any other listmembers using the SID chip: I have been using the 6582 because there
are much more of them available than the 6581. If i run it at 9V, the Audio output clips at the top. When
i increase the voltage to 11V, everything is fine. I have tried 4 different 6582, so i think it is not a faulty
chip. When i put a 6581 in the socket, there is no sound output at all with voltages below 11.5V.
Maybe the 6582 *needs* 12 V too ? I have changed mine to 10 V, so the clipping is reduced - i am not
sure how long it will survive when i run it at 12V.
Has anybody experienced that problem, too ? The output goes to ground with a 1K resistor, and then
has a unity gain follower after it. (the output itself seems to be very delicate - i zapped 2 of my SID´s by
shorting the output for the time it takes to insert a 6.3mm plug into the jack !)


-Michael Buchstaller