This repository contains the disassembly of an ISIS-II emulator for CP/M. The emulator was apparently written by Digital Research as it is based on CP/M 2.2 BDOS, although it doesn't contain any copyright notice. The emulator was found on the Unofficial CP/M web site, "Digital Research Binary Files" page, "Languages" section, among the "PLM compilers". Especifically, inside the plm80x80.zip file: IS14.COM and ISX.COM (the two files are the same).
The original ISX.COM file will not run under a standard CP/M system, as it requires a tailored BIOS and a slightly modified BDOS. You can find more information here. This repository contains the BIOS souces and binaries necessary to run the emulator on the P112 CPU platform.