Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

tony duell ard at
Tue Jul 14 16:28:20 CDT 2015

> > However, such designs are very few and far between. I will guess that if you took just about any of the
> > discrete transistor or TTL-baased minis or desktops and fed the design straight into an FPGA compiler then
> > it will not work.
> What machines were you thinking of?

I would be very surprised if you took the schematics for an HP9830, PDP8/e, PDP11/45, Philip P850, PERQ etc
put them into a schematic capture program and had a completely working FPGA version of the machine.

> Once TTL came out, 8,16,32 bits ended up being the common size.
> I working on FPGA computer design, that is TTL style computer, 1975 ish
> or so. 20 bits, 74LSxx 181 alu and 4x4 ram for general registers.
> I have not yet made up my mind how to do Interupts,but I got most the
> logic with only about 6 or so clocks.

If you mean 6 different clock sources (i.e. clocks delayed from each other, etc) then that
is not typical of a 1970s minicomputer in my experience.


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