Category Archives: DOS Extenders

Unintended Side Effects

Posted on May 23, 2023 by Michal Necasek

I’ve been lately trying to understand and improve the idling behavior of DOS programs and one of my guinea pigs has been the Open Watcom vi editor. While the 16-bit real-mode DOS variant of the editor idles nicely, the 32-bit … Continue reading →

Posted in Development, DOS Extenders | 1 Comment

EMM386 and VDS: Not Quite Working

Posted on February 26, 2020 by Michal Necasek

The other day I set out to solve a seemingly simple problem: With a DOS extended application, lock down memory buffers using DPMI and use them for bus-mastering (BusLogic SCSI HBA, though the exact device model isn’t really relevant to … Continue reading →

Posted in Bugs, Development, DOS Extenders | 2 Comments

Book Review: Unauthorized Windows 95

Posted on October 9, 2014 by Michal Necasek

A Few Decades Late Book Reviews Unauthorized Windows 95 Developer’s Resource Kit, by Andrew Schulman IDG Books, November 1994; 593 pages, ISBN 1-56884-305-4; $39.99 A testimony to the incredible level of hype surrounding Microsoft’s “Chicago”, Unauthorized Windows 95 was published nearly a year before … Continue reading →

Posted in Books, DOS Extenders, Windows 95 | 16 Comments

Floating-Point Exceptions and DOS Extenders

Posted on September 5, 2014 by Michal Necasek

Recently I had a need to test the behavior of floating-point exceptions (FPEs) in environments where traditional FPE reporting is used. To briefly recap, in the original PC equipped with an 8088/8087 pair, floating-point exceptions, which are generally asynchronous events, were … Continue reading →

Posted in 386, Bugs, DOS, DOS Extenders, PC architecture | Leave a comment