Collaborate Disseminate
[Michael Wessel] found some of his old DOS 3D graphics software and tried to run it on an 8088 PC. The tale of adding an 8087 co-processor to speed up …read more Continue reading A Forgotten Consumer PC Becomes a Floating Point Powerhouse
Even with ten fingers to work with, math can be hard. Microprocessors, with the silicon equivalent of just two fingers, can have an even harder time with calculations, often taking multiple machine cycles to figure out something as simple as pi. And so 40 years ago, Intel decided to give …read more
Continue reading Looking for Pi in the 8087 Math Coprocessor Chip
Most of us have been there. You build a device but realize you need two or more voltages. You could hook up multiple power supplies but that can be inconvenient and just not elegant. Alternatively, you can do something in the device itself to create the extra voltages starting with just one. When [Ken Shirriff] decapped an 8087 coprocessor to begin exploring it, he found it had that very problem. It needed: +5 V, a ground, and an additional -5 V.
His exploration starts with a smoking gun. After decapping the chip and counting out all the bond wires going …read more