Into the OS/2 Multiple Virtual DOS Machines: A better DOS than DOS after all

OS/2 provided an often overlooked but superiour environment for running many concurrent DOS applications: Discover the power of OS/2's Multiple Virtual DoS Machines! And it's more capable than you think, as it could even boot into CP/M, and, with some restrictions, also MS-DOS 7.x (aka “Windows 95“, just *without* the GUI). But there's some caveats, like the dreaded GATE A20, and also hard drive access needs some tinkering. Anyways, say hello to OS/2, the “Better DOS than DOS“! 00:00 Intro 00:42 Into the OS/2 DOS MVDM 02:11 Booting DOS into the MVDM: From MS-DOS 4 to MS-DOS 7, PTS-DOS and others 05:10 The Culprit about Windows ME and the A20 Gate 07:48 OS/2 MVDM without full Hardware Abstraction 08:36 How To configure a guest DOS for MVDM 09:53 Dealing with Hard Drives and I/O Errors 12:28 How To exit from the VDM 13:08 Decreasing Boot Time: Starting from C: 14:28 Decreasing Boot Time: Using Disk Images 16:27 Loading Win-OS/2 from a custom DOS VDM 17:18 Loading Win-OS/2 from a MS-DOS 7 VDM 18:05 Pushing the OS/2 MVDM: DOS 1.0 and CP/M 19:27 Conclusion 19:49 Next on TPC: OS/2 “drap door“ and Windows 95 Technical Manuals about OS/2: Additional reading about OS/2: Alternative DOS variants: General Information about CPUs: Specifics in context of V86 mode, Real Mode, and the A20 gate: Sources for Vintage Operating Systems: IBM PC AT: Visit also THE PHINTAGE COLLECTOR website at for insights into my retro computer collection. Copyright @ 2024 THE PHINTAGE COLLECTOR, Gianpaolo Del Matto. All rights reserved. Theme Music composed by Abdallah El-Ghannam.