Allison wrote:
On 6/19/07,
woodelf <bfranchuk at jetnet.ab.ca> wrote:
Providing the word length is a multiable of 4
bits that is.
It sure would be "fun" to debug microcode issues with nine
of those
puppies chained together.
Ignoring race conditions 9 of them are no harder than one.
The nasty is propagation delays. A machine that you can
microcode single step or slow step makes life easier.
I did an "improved 8080" a bunch of years ago using 2 and
it was fun. I have a dozen or so 2901Cs that were supposedly
the fastest of the TTL flavor. Though the ECL parts were much
faster.
I'm toying with the idea of a uCode testbench for a while already.
To have an FPGA(yes, I know, not everybody likes them) and a SRAM which
is at least 64 bit wide for microcode. The uCode gets downloaded via V24
or SD-Flash, then just the standard set of periperals like V24 (2), and
a bus interface, probably with some SDRAM already.
But, as usual, I can do it only in my spare time ;-)