TTL homebrew CPUs
bfranchuk at jetnet.ab.ca
Fri Jul 6 13:56:59 CDT 2007
Jos Dreesen / Marian Capel wrote:
>> 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.
> I made, in 1986, a 12 bit machine with raw TTL.
> Switches as input, 4 nixies as output, ca. 120 IC's.
> Parallel, with 3x181 as Alu, 3x194 as accu/shifter, and a dedicated
> hardware stack separate from the main 4Kx12 memory.
> Actually building and debugging it was the hardest part.
> Go for parallel, it is easier and will not be that more expensive in
> Let me know if you want my schematics
He may not but I do!
I can't resist nixie output. :)
PS. To the original post: Since you found magic , there is a lot of other CPU's
on the "Homebuilt CPUs WebRing"
Also the latest design I working on uses about 26 LS parts for control
and 4 512x8 proms. Using proms really simplifies your control logic.
This is a 24 bit cpu on three cards - control logic on one, 2901 bit
slice on two cards. The alu card is about 14 LS chips + 3 2901's per
card. Since this is a *slow* machine I can use ripple carry and LS
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