Learn Something Old Every Day, Part XX: 8087 Emulation on 8086 Systems
Summary
The article provides a detailed historical overview of 8087 emulation on 8086/8088 systems, covering the E8087 libraries, linker fix-ups, and the collaboration between language translators, linkers, and runtime libraries. It compares Microsoft's and Intel's approaches, explains the fix-up mechanism (e.g., FIDRQQ, FIWRQQ) and segment overrides, and discusses no-emulation modes and debugging support. The piece highlights the elegance of the emulation architecture and its impact on software portability in the pre-FPU era.