A reverse-engineering effort by the Opcode Collective examines the microcode of Intel's 1980 8087 floating-point coprocessor, focusing on the FSCALE instruction. Despite being a seemingly simple scaling operation, FSCALE uses over 140 micro-instructions across three levels of subroutines, revealing hidden complexities and features of the chip.
Background
The Intel 8087 was the first x87 floating-point coprocessor, introduced in 1980 alongside the 8086/8088 CPUs, and became the foundation for all modern floating-point arithmetic standards. Reverse-engineering efforts like the Opcode Collective's work continue to uncover technical details about classic semiconductor designs.
- Source
- Lobsters
- Published
- Sep 13, 2026 at 04:55 AM
- Score
- 6.0 / 10