1) is the HSC at a different software address compared with the old HSC I already have?
They are at the same address. If the XM BIOS detects a HSC pass through cart plugged into the top slot it displays an error message. If it detects a multi-cart it disables its own built in HSC because it doesn't know what you'll choose to play. If you are mad enough to plug an XM into an XM it detects that too.
2) Same question, but about POKEY software address for "special hardware" carts vs. XM.
XM POKEY does not conflict with CC2, Ballblazer or Commando POKEY addresses. It is compatible with the XBOARD games BeefDrop and Froggie.
Ok, this is good to hear.
So, in theory, there is no software change needed for say, newly-written software to be "XM compatible" with respect to the POKEY and the HSC, right?
In short, I'm trying to confirm that developers only need to make the software "one way".
So, if I wrote a game that used HSC, I'd have the option to use my old HSC, or to use the XM without code changes.
And, if I had a game that used POKEY, I wouldn't have to compile 2 different versions, one for XM, and one for "hardware that supported POKEY", correct?
That was something rattling around in my brain today; thought I'd ask the experts.