86-DOS

86-DOS
Booting up the 86-DOS system
Type:	Singletasking, Singleuser
Creator:	Seattle Computer Products
Architecture:	IBM PC
This Version:	1.0 (1981)
Date Released:	1981

86-DOS was the CP/M work-alike that was being written by Tim Patterson.

There is a great information site http://www.86dos.org/index.htm

One thing that is interesting about 86-DOS on the S-100 type machines, is that unlike the IBM PC the S-100's could access the full megabyte of RAM. According to Tim Patterson this feature was used within Microsoft until the creation of 32-bit tools to link the linker that Microsoft had built because it needed so much memory. Although I was always under the impression that Microsoft had their compilers ported to a VAX and cross-compiled stuff from there as it was faster, and didn't have the same memory limits... but that's from some un-based rumor I heard so you know... grain of salt.

How do I get this to run

There is a download like available to a SIMH image of the boot disk here Simple download the zip file & extract it, then use a version of SIMH's 3.0 or higher Altair Z80 emulator to bootstrap it. Although the name may seem misleading, the Altair z80 simulates a development environment that allows for an 8086 co-processor to execute the 86-DOS Operating System.