I've been thinking more and more this last week about designing a CPU to be
built from TTL logic ICs, purely as an interesting exercise.
I'm thinking of a microprogrammed design with a pretty minimal register count
- but as speed is never going to be a defining aspect anyway using commodity
TTL, I'm thinking of going for a bit-serial ALU to keep the parts count down.
Keeping the raw components pretty basic is another desired goal - no custom
off-the-shelf ALU chips, gate arrays etc.
Questions: have any others on here done stuff like this, or have any pointers
to good resources? I'm learning as I go along here, flicking through technical
manuals for 8-bit CPUs etc. and gleaning what I can from the web.
MAGIC-1 is about the most comprehensive online resource I've found so far, but
I believe it's a pure parallel core, and plus it's *way* more feature-rich
that what I'm aiming for. I'm not interested in running UNIX-a-like software,
or giving it hard drive interfaces or network stacks - I just think it'd
perhaps be fun to design and later build something from scratch to do basic
computation.
cheers
Jules