Re: Todd's ELF-ish gets some more I/O #ELF #Homebrew

Lee Hart

taf123 wrote:
This next device is a departure both from the CDP1800 series and from
the CMOS technology I've been leaning towards so far.

It's an AM9511A-1DC Arithmetics Processing Unit, or APU, by AMD. The
original AM9511 was from 1978, and my AM9511A-1DC is (c)1979, so it's
That's a pretty powerful chip; both in calculating and in power consumption. :-) It will take some work to adapt something like BASIC or FORTH to use it for its math routines.

There is a CMOS alternative. RCA made the CDP1855 multiply/divide unit. It's less powerful than the 9511, but CMOS and part of the 1802 family. They are hard to get, but I have one somewhere.

In case I haven't mentioned it before, I'm mightily impressed by your ELF-is computer. You have also spent as much time documenting it as building it!

Fools ignore complexity. Pragmatists suffer it. The wise avoid it.
Geniuses remove it. -- Alan Perlis, "Epigrams on Programming"
Lee Hart, 814 8th Ave N, Sartell MN 56377,

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