Monthly Archives: June 2011

Windows/386 2.01

Posted on June 21, 2011 by Michal Necasek

The OS/2 museum recently obtained a boxed copy of the original Microsoft Windows/386. That is, version 2.01 of Windows/386 from September 1987. Windows/386 was Microsoft’s first product utilizing the 386 hardware in the DOS world. Microsoft was involved in the … Continue reading →

Posted in PC history, Windows | 48 Comments

DOS Memory, Managers & Extenders, Part I

Posted on June 17, 2011 by Michal Necasek

To understand why the maddeningly complex world of DOS memory managers and extenders came to be, it’s necessary to understand the evolution of the PC platform. Even though memory managers and DOS extenders reached their peak on 32-bit 386 and … Continue reading →

Posted in DOS, PC architecture, PC history, x86 | 27 Comments

The IHC Damage

Posted on June 14, 2011 by Michal Necasek

Trying to sort through a heap of floppy images recently, I found many of them to contain a suspicious ‘IHC’ signature in their boot sector in the location where an OEM identifier (such as ‘IBM  3.3’ or ‘MSDOS5.0’ would normally … Continue reading →

Posted in DOS, Windows, Windows 95 | 5 Comments

Interrupt 68h and EMM386

Posted on June 8, 2011 by Michal Necasek

While working with a modified BIOS image in a virtual machine, I ran into mysterious hangs when trying to load an old version of EMM386.SYS from MS-DOS 4.01. A newer version of EMM386 did not exhibit the problem. A quick … Continue reading →

Posted in BIOS, DOS, Virtualization | Leave a comment

Researching the history of PC computing

Posted on June 2, 2011 by Michal Necasek

Finding out what happened in the world of PC computing 20 or 25 years ago isn’t always easy. The 1980s were over before the Internet took off, which means that most of the information was never publicly available in electronic … Continue reading →

Posted in PC history | 2 Comments