SID2SID incompatibility

[DrKucho Games]

I have two machines with a dual Sid board called "SID2SID" https://www.mssiah.com/features.php#sid2sid

messiah cartridge refuses to work, it shows the boot menu but it won't receive any dada by midi, even the red led for midi in gets lights when transferring programs with kerberos app pn the pc but no real data gets into the machine

I just found that unplugging the SID2SID board the midi in will work 

and it happens exactly the same in both machines with SID2SID installed

any solution?

[_ C64 CUSTOMS _]

The Sid2Sid ist designed to work with Mssiah so I assume that there is some kind of installation problem. Is the additional wire attached to the correct pin on the expansion port? It should be pin 7

Have you assembled the kits by yourself? Are there any solder bridges between some of the pins of the sockets maybe? If Mssiah isn't booting up to the menu then there is very likely an address conflict.

I'm a bit confused by the mix of Kerberos and Mssiah, do you try to run both cartridges at the same time on the same machine?

[DrKucho Games]

thanks for the reply 

I don't plan to mix messiah and kerberos, I try to replace messiah interface by kerberos , messiah works fine with the sid2sid board, the yes I assembled myself and yes there is a cable soldered to pin7 on the cartridge port, and .. yeah been making music with messiah and sid2sid for some time with these machines, but now I want to use kerberos and a modified own sidwizard version that can take much more power of midi 

I just read on SID2SID documentation that seconds if is configured at DE00 , sidwizard can use different addresses for the extra sids, so that shouldn't be a problem, but hey... i need it to receive midi first on kerberos, I wonder if there is a conflict with DE00 and kerberos using this address for MIDI ...?

[_ C64 CUSTOMS _]

I haven't tested it yet for myself but as far as I remember is $DE00 causing issues with the old Kerberos cartridge. I'm using Kerberos and Cynthcart and had to use a different version, which runs on a different address, and my Mixsid (twin SID adapter) is configured to, I think, $DF00.

Since there is no chance to change the address on the Sid2Sid directly, you need so solder the wire to the 10th pin of the expansion port, which should give you $DF00 then.

[DrKucho Games]

I was reading about pin 10 and DF00 in a forum, but I wasn't sure that would work for SIDSID as well, thank you, ill try that !

hey I wanted to buy a MIXSID as well, I wrote the guy but I never got response, I thought he was out of business..? do you know if he is still shipping those kits?

K

[Frank Buss]

SID2SID at address $de00 or address $df00 doesn't work with Kerberos. You need a SID adapter for $d420, which is supported by Cynthcart as well.

Someone asked me this by eMail some time ago and I suggested the following:

But it should be possible to mod the sid2sid with a simple 74LS00 quad NAND, if you have some electronics experience. The CS line for the original SID goes low in the area $d400-$d7ff (this is the reason the first SID is mirrored in this area). If you disconnect this signal and use the NANDs to generate the CS signals for both SIDs in combination with address line 5 (the xx20 selection), it should work.

CS SID 1 = !CS NAND !A5
CS SID 2 = !CS NAND A5
!A5 = A5 NAND A5
!CS = CS NAND CS

You could even make CS SID 2 switchable and mount the switch in the C64 case, so that you can change between $d420 and $de00.

He did wire up this circuit and it worked. PS: "!CS" means "not CS" and can be done with one NAND gate, or an inverter like the 74LS04.

[DrKucho Games]

I just tested it and ... while midi works during the the file transfer, once if finishes and the cartridge wants to start the program it won't work, I get a blank blue screen and nothing happens, I think kerberos also uses DF00 for memory transfers or something

[DrKucho Games]

hello frank, thanks for this info and modification suggestions , sounds like something I can do, Im not bad soldering and following instructions, but im not an expert to understand exactly how to do it, I would need a diagram or something similar, did you know if the other guy finally did it? he might want to share some pictures with me

[Frank Buss]

This should work:

http://www.frank-buss.de/kerberos/sid2-circuit.png

So you need only one 74LS00. It should be the "LS" version, because it is faster and avoids problems with setup/hold times. For the capacitor C, use 100 nF, close to the chip, but might also work without one. The numbers on the gates show you the pin numbers for the 74LS00. If you have already the SID2SID, you can just bend the CS pins of the SIDs and solder wires to it, or scratch the traces to the CS pin and solder wires to the traces (but this is more fragile). Then use a perfboard for the 74LS00 and connect all wires. The C64-CS signal is the original CS signal for the SID, and you can get the C64-A5 signal e.g. from a pin on the expansion port, easy to solder.

[DrKucho Games]

this is so amazing, thank you! , i think I understand everything clear enough, but I will check with a friend of mine who knows much more about circuits before doing anything!

K

[DrKucho Games]

I must be doing something wrong cause it doesn't work, no sound is coming out from SID 1, I'm testing with kerberos boot option A (about) which include a song, I didn't test SID2 I asume its not working either

chips are fine if I take them out and insert them in the C64 socket with no SID2SID board they do sound

I checked conductivity again and again but everything seems fine, could you check my picture to ensure I got your instruction sok? I hope the picture is clear enough, note the pins are inverted cause the chip is upside down in the pic

the hot glue mess is because that pin is cut, that is the CS pin and, in order to disconnect it from SID1 I cut it on the base , then I bent the leg wire that I just cut into a L shape , I soldered to one of the black cables and used hot glue to hold it in place and insert into the C64 SID socket to get the CS signal while is NOT touching the surface of the SID2SID board because there is the return to SID1 CS, seems a bit risky but conductivity test was fine

I also measured voltages with the machine switched on and I get 4.5v (approx) in all CS , the one coming from the C64, and the two 74LS00 CS outputs , I am not sure if this is what should happen...

[Frank Buss]

Looks like the connection from pin 3 to pin 9 of the 74LS00 is missing. And some of the solder joints could be cold solder joints, like the supply voltage red cable on the SID2SID board, or the connection on pin 8. Maybe resolder these two.

[DrKucho Games]

Oh my goodness! Pin 3 to 9 !!! I don’t know how I missed that 😓, thanks!

[DrKucho Games]

Good news ! It works now after soldering 3 and 9
Thanks again for the help and for designing Kerberos 👏🏻