> > 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. -tony