This next device is a departure both from the CDP1800 series and fromThat'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, www.sunrise-ev.com