SID chip to add stereo sound to 64 + 1902A monitor in 80 column mode

[videohobbieperson]

Correction per C128 manual 2nd edition 40 column mode is via round DIN connector and my testing my C128 computer out confirmed this. I been able to get in to both 80 and 40 column modes though was not able to get the 64 mode to work in the 80 column mode though could get the 64 mode to work in the 40 column mode. On the C128 computer is it possible to get it to work in both 80 column mode and 64 mode at the same time and if yes how??
On the Commodore model 1902A monitor when it is in 80 column mode is it only one color you can get? If yes what is that color? How many colors and shades of colors can one get on the Commodore 1902A monitor is 80 column mode. Does anyone know about where to get a SID chip to add stereo sound to a 64/ 128 computers and how to install it??

 

[RetroHacker_]

The Commodore 64 mode will not do 80 columns. The original Commodore 64 cannot do 80 columns.

Adding stereo sound is pretty simple. Just google for it and you'll find the plans. I've never done it to a 128 though, but it should be doable. It involves piggybacking another SID chip on top of the one that's in there, and bending out a couple of pins (paddle inputs, audio output, and chip select), and building another amplifier circuit. And, of course, wiring up the chip select line.

You can get another SID from a junked 64, or eBay.

-Ian

-Ian

 

[Dave Farquhar]

Like Ian said, the VDC (80 column chip) wasn't supported in 64 mode. It was possible to hit the chip directly in machine language, and there were a few programs that did it, but there wasn't a lot of point. If you wanted 80 columns, you might as well write your program to run in 128 mode.

A few disk copy utilities used the VDC chip's dedicated memory as a buffer on 128s running in 64 mode, but that was the most practical use of it.