SID Chip Upgrade

Rob Murphy · Post by **Rob Murphy** » Sun Jan 30, 2005 3:39 am

I was wondering if it would be possible to put a SID chip on a cartridge and use it with a Vic 20. Has anyone ever pondered this idea?

Mobsie · Post by **Mobsie** » Mon Jan 31, 2005 3:02 am

Hi,

maybe it will work. The Atari User do this with the Atari 8-Bit's.

Nice question.

Cheers

carlsson · Post by **carlsson** » Mon Jan 31, 2005 5:35 am

According to the Battleships docs, there used to be SID chips interfaced with the VIC-20. I've never heard about it before, but the game supports a 6581 chip mapped at $9140 (i.e. right after the VIAs).

Rob Murphy · Post by **Rob Murphy** » Mon Jan 31, 2005 11:15 pm

Mobsie, Could you give me a web site for the info on atari, so I can study this a little more. Also, Anders, I'd like to get a web site I could get that Battleship info from.

That would be the next thing I'd put on a wish list.

1. 40k RAM Expander.
2. Sid Expander
3. 40/80 column Card

Maybe someone can get some sprite control too.Hey, I just made a motley64. LOL. Oh well, I can dream (because I probably don't have the know how to make something like that myself).

Thanks for the help.

Mobsie · Post by **Mobsie** » Tue Feb 01, 2005 2:29 am

Hi Rob,

on the http://www.abbuc.de site you find a lot of stuff. I am member and i became an printed magazine 4-5 times in year.

In this magazine i found the articel about the SID stuff. I remember there was an link. I will lot at home ( in moment i am on work) an then i post the link here.

Cheers
Mobsie

carlsson · Post by **carlsson** » Tue Feb 01, 2005 3:37 am

Rob, check http://www.cbm.sfks.se/files/ but I haven't looked into the actual program to see if it really tries to address a SID at the mentioned address. There are no technical docs how to build a cartridge anyway.

The Plus/4 quite commonly interfaced an external SID chip at $fd00 IIRC. I don't know which "latency" you get with a chip on the cartridge port, but at least you should be able to play the simple music that doesn't alter the register values one hundred times per second.

Rob Murphy · Post by **Rob Murphy** » Sat Feb 05, 2005 7:16 pm

Thanks guys for the info.