Hi,
Oh i didnt realize that you were not using the entire 64k address space. With 32k ram and only 2k rom, you have some of that address space available, unless of course you intend to increase the size of the rom, and then you should use i/o anyway. But if you can limit the rom to say 16k, then that gives you one address line that wont be used for addressing anything when the ram isnt selected with A15, so you can use that AND'ed with A15 to access 16k of something else, like your sound chip or similar. So you would AND an inverted A15 and non inverted A14 and that would be your enable for that missing 16k space. This means that you cant use that for addition ram in the future though too, unless you provide more gating and limit the ram to something smaller than 16k. Bank switching is always an option too though if you dont mind the extra complexity.
An edge connector...
You mean a PC board edge connector? To plug into what, the PC computer or your own mainframe card cage? One way is to use those Datak rub on patterns before you etch. They come in various widths and spacings, although i dont know if they come in the PCI bus dimensions. I did one myself but it was for the older AT connectors which had larger prongs.
An alternative is to buy a ready made perf board with an edge connector already on it, if they still make them. If not, maybe cut one off of an old board and epoxy it and possibly bolt it to the board you make with maybe 2-56 size hardware, or maybe 4-40.
This is interesting to me because i used to use the Z80 a long time ago. I had two commercially made computers with the Z80 too, the well known Sinclair and the TRS-80. I also made a controller board with the Z80 and one with the earlier 8080.