Love these deep dives. It’s fascinating to see how real, low-level engineering we all take for granted today unfolded. It’s incredible that the rough equivalent of an entire 160lb digital computer was built and baked into silicon.
Also incredible reverse engineering. In a time when seemingly all appreciation for expertise is gone it’s so refreshing to see.
kensSep 26, 2026, 5:44 PM
Author here for your 8087 questions...
WalterBrightSep 27, 2026, 12:14 AM
Thank you! Amazing work! I've always had a soft spot for the 8087.
Maybe implement the algorithm in C? Thank would be fun!
jacquesmSep 27, 2026, 2:10 AM
Weitek next?
kensSep 27, 2026, 3:07 AM
The 8087 is probably enough floating point for a while :-)
jacquesmSep 27, 2026, 7:52 AM
That's an interesting chip though, but probably also much more challenging.
cmovqSep 27, 2026, 1:40 AM
Always thought it was strange that fptan also pushes 1 to the register stack. It now makes sense it’s so existing code for the 8087 which was expected to do y/x to get the actual tangent could keep working by doing y/1 on newer processors.
Const-meSep 27, 2026, 9:08 AM
I remember I once wanted to compute tangent of fp64 vectors. Here’s what I did.
Also incredible reverse engineering. In a time when seemingly all appreciation for expertise is gone it’s so refreshing to see.