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Im creating a IBM AT clone for the fun of it, only chip Im missing is the actual cpu, (intersil still sells an 8088 clone) I have a UART, PIC, PIT, RTC, et al, but there was two things that were literally impossible to find because no one fabricates them any more, that is the 8042 keyboard controller, and the CGA card.

To compensate for this, I have decided to use a parallax propeller, which is a 40 pin DIP microcontroller with 8 "cogs" and built in video corcuitry for NTSC for a multi-io chip. On this chip, I am going to emulate a single channel 8042, a SID (Cause if Im gonna have sound, Im gonna do it with style) and a video device. Needless to say with 32 I/O and full bus logic this doesnt leave many i/o for extras.

My perdiciment comes down to the following, with the graphics emulation, I have 16k internal ram on the propeller I can use for VRam (bus logic I/O has 14 addr lines) And with NTSC I have about 32 million colors I can display using color hacks. So which video chip should I emulate? CGA is good, but I could emulate a VIC-II, MDA, or make one up on the fly.
Resolution is limited by NTSC BTW, so no hi res vga, not like I'd have the memory for it.

What would you do?

I would just get myself an ISA slot and some oldfashioned VGA-compatible card from the second-hand market (in my case, the attic), to make it actually PC-compatible. Otherwise, you'd end up being best off with an tile-based engine console style to get the best graphics for the available RAM.

Have a look at this:

http://www.malinov.com/Home/sergeys-pro ... ergey-s-xt