MDOS - Micropolis PDS/12 version 4.0

The Micropolis "Program Development System" consists of the MDOS operating system along with an assembler, BASIC and other utilities. The console device is unconfigured on the distribution disk and is easily modified for a variety of early computers (e.g., Altair, IMSAI, Sol-20, Vector Graphics, etc.). Configuration steps are provided in the MDOS manual.

Alternatively, MDOS disk images already configured for a particular computer are available for the Altair 8800, Sol-20, and Vector Graphic computers in the corresponding download directories on this website. The PC2FLOP utility for writing a physical disk from the disk image is available for each of these computers in the corresponding directories as well.

MDOS for the 35 track (Mod-I) and 77 track (Mod-II) versions differ only in the file "RES" which contains a four drive table with the number of tracks per drive. The table is located at 0884h-0887h within RES. The table contains 35's (23h) for the Mod-I drive and 77's (4Dh) for the Mod-II drive.