Commodore 64 Ultimate Config Questions

[synaptyx]

I'm pretty much a raw n00b here, so please bear with me.

I bought two SIDKick Picos recently and tried to install them both in my C64U tonight, but when I have both in there, I can't get the config screens up.
They work perfectly individually, so I just wondered if you can even have two installed at the same time in a C64U.
If it is possible, could some kind soul share their config and maybe some pointers with me?
If I can't run two SIDKicks in a C64U It'd be great to know, then I will probably just sell one on (for my cost plus post).

Thanks!

[marty41]

You of course can have both SIDkicks installed in your C64U at the same time. But if you want to start the config tool, you have to only set one of the SIDkicks to $D400 and start the tool with SYS54301. It isn't possible for the C64U to distinguish which SIDkick is meant when both are set to address $D400. So just set the address of the other SIDkick to any address not matching $D400 and set up your 1st. SIDkick. After that, switch the addresses and set your 2nd SIDkick to $D400 and set it up. If you are done, you can set both SIDkicks to whatever address you would like them to listen to.
A SIDkick is able to emulate two SIDs internally and set the second internal SID to an address selected with the available address lines A5, 6, 8, IO1/2. But be aware, that on the C64U there is no easy way to mix the output of the 2nd internal SID to the opposite output side on your HDMI output. So both SIDs are output either to left or both to the right. Real stereo isn't possible this way.
If you want stereo, you need to use the 1st SIDs of both SIDkicks. you must use both SIDkicks together. For example, SIDkick1 (panning left: 5) at address $D400 and SIDkick2 (panning right: 5) at $D420 and ignore the 2nd SIDs in both SIDkicks.

[synaptyx]

Thank you Marty, that was very helpful! I think I get it now. 🙂