Still catching up with this thread - it's kind of information dense.
I just wanted to drop in another IC that you might like to check out. The Cypress Semi PSoC series - Programmable System On Chip. They're a CPU core (your choice of ARM or 8051) with a wad of FPGA/CPLD-like glue logic surrounding them, and looots of IO pins. Relatively cheap. There's a low-cost dev board on Kickstarter called FreeSoC - it may have launched by now.
Also, if you have your heart set on a 6502-like flat memory-mapped IO system, have you checked out Sprow's MiniB - a floppy-sized SBC based on the BBC Micro?
In any case, if bigmessofwires can build and design a CPU and OS from scratch out of TTL logic, I say hang the practicalities and chase that dream! If the purpose is self-education and amusement, do it your way.
But if, like me, you are easily discouraged and distracted, treading a path already partly worn by others may well help, at least for Mark 1.
I just wanted to drop in another IC that you might like to check out. The Cypress Semi PSoC series - Programmable System On Chip. They're a CPU core (your choice of ARM or 8051) with a wad of FPGA/CPLD-like glue logic surrounding them, and looots of IO pins. Relatively cheap. There's a low-cost dev board on Kickstarter called FreeSoC - it may have launched by now.
Also, if you have your heart set on a 6502-like flat memory-mapped IO system, have you checked out Sprow's MiniB - a floppy-sized SBC based on the BBC Micro?
In any case, if bigmessofwires can build and design a CPU and OS from scratch out of TTL logic, I say hang the practicalities and chase that dream! If the purpose is self-education and amusement, do it your way.
But if, like me, you are easily discouraged and distracted, treading a path already partly worn by others may well help, at least for Mark 1.