Tricky where to put this question.

First question is how many things out there support twin SID equipped C64? Will existing games or music apps not written for dual SID crash?

Of those modified games/apps/songs that are designed for dual SID where can I find them to download?

And finally would these also work if I check the "stereo SID" box in VICE SID Settings?

See so it covers a few areas, sorry if general C64 is the wrong section to post this in.

Thanks.

I'm adding to this questions about the cartridge that was released with an extra SID on it - will that benefit in similar ways as if it was put into the C64 and linked to the original SID chip?

Would addressing of extra SID chips be done by using original SID registers + $0020 for the second SID? That would be $d418 for sound level on SID1 - $d438 for sound level on SID2 - correct? If not, how would you address the extra SID chips?

In VICE you have to set the address for controlling the second SID if you select stereo SID too.

Also a few website hinted at doing this DIY but there are no details. They just say you piggyback the second SID on the first but omit the details of exactly what is done and what components you need.

You can get a SID2SID board that makes adding a second SID compartively easier, but if you're a bit crazy you can hack one in there.

I managed to hack a second sid and piggyback it on the first chip on one of my old C64s. It is doable, but not for the faint of heart. SID chips are hard to get and you don't want to damage the pins on one.

You solder a chipsocket on top of a SID chip and then mount another sid chip into that. I even slipped in a bit of heatsink into the socket to prevent some overhead. You also need solder on some components onto the top chip in order for filtering to work. On top of this, you need to build a circuitboard with some more components on it, and then wire the whole she-bang into your case with a switch.

There is a stereo-sid player for the C64 and there are songs that can play the full 6-channels. (there's an awesome 6-channel version of Axel-F)

Probably the best use of having twin SID chips is with a MSSIAH cart that enables you to sequence music for all those channels:-


Link


Link

Hello Neo

Where can I find 6 channel SIDs? Special section in HVSC?

They are named with the suffix *_2SID.sid so they are easily found.
if you use PSID64 0.9 (http://csdb.dk/release/?id=104424) you can make standalone prgs also from stereo sids and run them on a real c64, if you have a 2nd sid at the address specified in the sid tune header.
Else use vice or any updated sid player that already know how to play the v3 2SID files =)
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The plug-in cartridge is functionally the same as putting it on the motherboard. Electrically speaking, all the same address lines are available on the cartridge port.

The benefit of the cartridge was less heat, and the benefit of putting it on the board were keeping the cartridge port free for RAM expansion or a fastloader.

A plug-in board with two SID sockets (like a SID2SID) is a nice solution, as long as your board had a socketed SID. It gives the benefit of better heat dissipation while keeping the cartridge port clear.
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Sure, you'll possibly hear strange music, but does that count as a crash?

I don't see how the program would start behaving unexpectedly or quit running.

Edit: I was wrong, you can use $d420 in Commodore 128 as 2nd SID-adress as well if you'd like.

really? I knew it was $d030. VIC regs are mirrored at SID address space?
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Yeah, I probably got $d420 and $d020 mixed up when I tried some 2SID stuff. Woops.