prindle@NADC.ARPA (Frank Prindle) (02/14/89)
Please note that it is *NOT* necessary to modify your C64/C128 to add a second SID chip! In fact, it's not even cost effective considering all the work necessary and adding a switch, etc. You can purchase the extra chip already built into a cartridge that you just plug in: it's only $34.95 from Dr. Evil Laboratories, P.O Box 190, St. Paul, IN 47272. If you need a copy of Stereo Sidplayer, send them an extra dollar for a sample music disk. The Stereo Sidplayer (up to about version 10.2 now) is by Mark Dickenson, is public domain, and continues the tradition of the "Sidplayer" family of music software in that it is truly outstanding (see my previous review of Craig Chamberlain's book/disk Enhanced Sidplayer system). The cartridge works on any 64, 128, or SX, and was extensively demonstrated at the Nov 88 World of Commodore Show in Philadelphia. If you must install your own 2nd SID chip, be careful not to mix 12V and 9V chips: if your machine has a 12V chip, then piggyback a 12V chip; if it has a 9V chip, then piggyback only a 9V chip. Also note that the SID filter capacitor values are different for 9 and 12 volt chips. The 6581 is a 12V chip, the 8580/6582 is a 9V. The filter caps should be 220pf-470pf for the 6581, but need to be much larger (e.g. 22000pf) for the 6582 for proper operation of the SID filters. I am in no way affiliated with Dr. Evil Laboratories, just a very satisfied customer. Sincerely, Frank Prindle Prindle@NADC.arpa