I figure anything CP/M is on-topic, but the hardware I'm talking about would be brand new. :) Are there working examples of CP/M running with just a serial terminal connection and a drive+interface for the sum total I/O? I'm assuming this has been done many times and in theory would be nothing too offbeat? If this exists, it might be useful to study the BIOS to see what's being done there, or perhaps just buy the board and CP/M if by chance something's out there already. Are you giving up anything important with a terminal-based CP/M system vs. one with integral monitor and keyboard -- in other words, cursor positioning and such in applications being less flexible? I'm assuming the answer is "no", no difference because of the way CP/M BDOS calls all go through BIOS? Or is this a "in theory X in practice Y" thing? The reason I'm asking is I've FINALLY -- after about two months of struggle with hardware and coding -- succeeded in getting my IDE interface working. Although it's currently mated to a 6502 board and a 60GB HDD, since it's based on an 82C55, could just as easily be coded to work with a Z80/Z180 system. Okay, I know that porting a BIOS to a new board would be massively non-trivial. I've got a good book "Programmer's Guide to Using and Modifying CP/M" (IIRC) which makes it clear it would be a fairly good prospect to take months to finish, even with good debugging practices. (Although I'm no stranger to coding moderate-sized assembly programs.) On the other hand, I'd motivated by having an SBC that could run any of a number of C, Pascal, Modula 2 or Fortran compilers, along with BASIC, decent editing tools (well, I cut my teeth on PC-DOS Wordstar!), would make such an SBC really quite nifty as a hacking toy. Comments? I'm thinking of using a GAL decoder to map 32Kx8 of "shadow" EEPROM to MEMRDs and the "shadow" RAM to the same address for MEMWRs upon RESET, then copy the "shadow" ROM to RAM on coldboot, and then write to an I/O port to cause the GAL to map only the 128Kx8 SRAM into the machine memory map and jump to 0 to bootstrap up. Not sure if BIOS could use the upper 64K bank for storage in a useful way like disk I/O buffering, but since 128Kx8 SRAMs are cheap and small, and I've got a tubefull, that's what I'd want to use. :) P.S.: I got the 360K floppy to work under Win98, but not XP. I suspect it's just an undocumented "feature" of XP. :)