Category Archives: DOS Extenders

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 | 14 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