TAG Posted December 2, 2013 Report Share Posted December 2, 2013 While digging into the retrocade project I thought about how easy it would be to control real chips, since the HDL chips are implemented with the same interfaces as the real chips it seems to me that it would be very simple to modify a SID peripheral for example to just connect the interface signals to IO and drive a real chip SID. It would be a great way to compare the real thing to the HDL versions, and a way to use real chips if you had them. Link to comment Share on other sites More sharing options...
Jack Gassett Posted December 2, 2013 Report Share Posted December 2, 2013 yes, it would be very easy to do, in fact when I was designing the RetroCade board I had considered adding a socket for an original SID chip... Jack. Link to comment Share on other sites More sharing options...
james1095 Posted December 3, 2013 Report Share Posted December 3, 2013 Just don't forget to put some level shifting between the FPGA and whatever old chip you're trying to talk to. It's really unfortunate that so few modern digital parts are 5V tolerant. It isn't particularly hard to get around that limitation but it's one more obstacle. Link to comment Share on other sites More sharing options...
alex Posted December 3, 2013 Report Share Posted December 3, 2013 I'm actually about to do this exact sort of thing shortly (not with a SID, different sound chip). If there is interest I can start a new forum topic and rant about it as I go along complete with pictures. Link to comment Share on other sites More sharing options...
rpflaum Posted December 3, 2013 Report Share Posted December 3, 2013 Alex,I would have interest in following that!! Link to comment Share on other sites More sharing options...
Jack Gassett Posted December 4, 2013 Report Share Posted December 4, 2013 Me too! Link to comment Share on other sites More sharing options...
TAG Posted December 4, 2013 Author Report Share Posted December 4, 2013 What chip? Link to comment Share on other sites More sharing options...
alex Posted December 4, 2013 Report Share Posted December 4, 2013 This chip. Link to comment Share on other sites More sharing options...
hamster Posted December 4, 2013 Report Share Posted December 4, 2013 I like that chip. Yes please! Link to comment Share on other sites More sharing options...
neslekkim Posted December 9, 2013 Report Share Posted December 9, 2013 I scraped ebay for some time ago and ended up with these 6581, SMC0608S, YM2203C, SAA1099P, SN76477N, AY-3-8910, but not that chip,damn..Got also some dacs:TDA1543, DIR9001, BB PCM61P, MCP4921, YM3016-D, YM3014B, YM3012 Are these types of chips difficult to wire up?, going to read that thread anyway, looks very detailed, kudos to that! Link to comment Share on other sites More sharing options...
james1095 Posted December 9, 2013 Report Share Posted December 9, 2013 Your best bet is to look up the datasheets for each of those chips. Most of these sound chips have similar interfaces regardless of how they function internally. Usually there is a clock signal and then a parallel bus is used to access a series of registers within the chip. The number and function of these registers is specific to each chip but the difficulty is similar. The hard part will be coaxing them into making sounds that are pleasant to listen to. For example, here's a datasheet for the AY-3-8910http://pdf1.alldatasheet.com/datasheet-pdf/view/166797/ETC1/AY-3-8910.html The other thing I would do is scour the internet for other projects incorporating the chips you are interested in using. There are quite a few chiptune synth projects out there. The DACs are probably not terribly interesting. You can get pretty much the same result with a resistor ladder or a delta-sigma DAC in the FPGA. Link to comment Share on other sites More sharing options...
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