Rendered at 16:01:34 GMT+0000 (Coordinated Universal Time) with Cloudflare Workers.
tasty_freeze 22 minutes ago [-]
Northstar made an S-100 card which did FP math, using BCD arithmetic. It had a ucode ROM and a 4b (single digit) ALU, and a few small RAMs to hold the digits. If I remember correctly you could program it to select how many digits you wanted in your representation, up to 14 digits. It did everything one digit at a time, and it had a 256 byte ROM to carry out any digit*digit product in one cycle. For normalization no data was moved -- just the pointer to the appropriate digit was incremented or decremented.
Yes - I was just trying to give things a "this is interesting, so upvote & discuss!" kick. In the absence of Ken popping up with good "Author here for your 8087 questions" comment.
elpocko 21 minutes ago [-]
I guess he didn't pop up because the article is 6 years old.
https://s100computers.com/Hardware%20Folder/NorthStar/FP%20B...
https://news.ycombinator.com/item?id=48519011 (about the 8087's adder)
https://www.righto.com/2020/05/die-analysis-of-8087-math-cop...
https://www.righto.com/2026/06/intel-8087-adder-reverse-engi...
https://news.ycombinator.com/item?id=23362673