开云体育

Hello everyone!

Good to see a bit of traffic here lately after a long lull. ?I know why I've been so distracted and I assume most folks have lots of stuff going on in their lives. ?

I'm finally getting back to a long-term CS80 renovation / mod project after moving and job changes and other fun stuff. ?I have a question for any of the techie types here. ? For review, all the digital logic in the beasts use standard (and mostly still available) CMOS chips. ?These are old DIP packages that only fit a hand full of gates in each chip. ?They are all run off of +8.5v and -6.5v. ?This weird arrangement fits in the 15-volt supply that the chips can handle and being offset allows analog switch chips (e.g. 4051, 4016) to process the analog control voltages and audio signals that are bi-polar around zero volts.

So, I want to add a bunch of new logic including an FPGA (tons of re-programmable gates) and a processor (maybe Arduino).

Again, the catch is that this board has 3.3volt digital I/O - which is actually pretty high compared to the latest chips! ? So, I need to translate a lot of signals. ?The old standbys were the 1488 and 1489 chips that were design to translate from 5volt TTL to +/- 12v (or lower) for RS-232 serial ports. ?I might be able to use these but they would take up a ton of room and I'm not sure if they'll work with 3.3volt instead of 5volt. ?I looked around a bit yesterday but found tons and tons of possible chips and was hoping someone here might know a good chip to use. ?I'd like something that's 3.3volt on one side and up to the +8.5v/-6.5v Yamaha levels on the other side. ?DIP or SOIC package would be fine and I'd like 8 or more channels in each chip with versions for one-way and bi-directional.

Any ideas on this idea in general? ?On the Mojo board? ?On the level-shifters?

Thanks and hope everyone is having a happy, music-filled summer!

?David