If you use Binary Ninja and have to look at 8086 binaries, here’s a new plugin that should help:
https://github.com/whitequark/binja-i8086/
Tag: 8086
bios-8088: disassembled BIOS from 8088 machines
Disassembled BIOS from 8088 machines
https://github.com/ricardoquesada/bios-8088
Speaking of old Intel chips:
https://github.com/jeffpar/pcjs
https://github.com/morphx666/x8086NetEmu
https://github.com/nkeck720/tiny-8088
The IBM BIOS reference was a classic, and archives of it exist online:
https://www.google.com/search?q=IBM+BIOS+Interface+technical+reference
Firmware Security 