As an entry into a completely standalone computer project, I wanted to avoid the ever-present 6502 and Z80 designs, purely out of a desire to be a bit unique. The goal here is simplicity, but without leaving out any major functionality. The following requirements are in mind:
1. Sufficient RAM and ROM to have some room to stretch and play with.
2. Parallel, serial, and analog I/O.
3. Potential video output and HID, however this is a secondary priority.
4. Expansion, preferably through an ISA compatible bus. I have a bunch of DIN41612 connectors so I will probably end up using those.
I would like this to also mainly rely on commonly available modern parts, as the supply for vintage ICs gets thinner by the day, and UV EPROMs scare me. I'll keep this as updated as possible considering my school work on the side.
Another thing is even though the 8251 is an Intel chip, most add-on serial cards, and later supercombo chips did not use this UART but rather the Natsemi 8250, then the 16450, and finally the 16550. So if you later hope to run DOS comms programs, the 16550 is what you want. I don't know its availability on the retro market these days. People like me may have one or three stripped from old PCs in their spares box.
Another thing is even though the 8251 is an Intel chip, most add-on serial cards, and later supercombo chips did not use this UART but rather the Natsemi 8250, then the 16450, and finally the 16550. So if you later hope to run DOS comms programs, the 16550 is what you want. I don't know its availability on the retro market these days. People like me may have one or three stripped from old PCs in their spares box.