Category Archives: Microsoft

Multitasking MS-DOS 4.0, Goupil OEM

Posted on April 9, 2014 by Michal Necasek

The recently unearthed copy of the near-mythical Multitasking (aka European) MS-DOS 4.0 clearly did not want to be alone. James Lariviere, a kind reader of this blog, provided a disk image of multitasking DOS 4 which was released in 1986 … Continue reading →

Posted in DOS, Microsoft, OS/2 | 30 Comments

MS-DOS 1.1, 2.0 Source Code Released

Posted on March 25, 2014 by Michal Necasek

In cooperation with the excellent Computer History Museum in Mountain View, Microsoft released the source code to MS-DOS 1.1, MS-DOS 2.0, and Microsoft Word for Windows 1.1a. Here’s hoping that this is a sign of things to come and Microsoft … Continue reading →

Posted in DOS, Microsoft, PC history | 53 Comments

IBM OS/2 1.0 in a VM

Posted on March 21, 2014 by Michal Necasek

As previously mentioned, IBM’s OS/2 1.0 and 1.1 is extra unfriendly to modern hypervisors. To recap, there is a curious difference between IBM’s and Microsoft’s kernels in OS/2 1.0/1.1 with regard to mode switching. For reasons that aren’t very clear, … Continue reading →

Posted in IBM, Microsoft, OS/2, VirtualBox, Virtualization | 36 Comments

Installing Oct ’91 NT from CD

Posted on December 15, 2013 by Michal Necasek

With VirtualBox 4.3, it is possible to install the oldest known pre-release of Windows NT directly from CD, the way Microsoft intended. This is the Fall ’91 Comdex preview which only supported the x86 architecture and a very short list … Continue reading →

Posted in Microsoft, NT, SCSI | 35 Comments

Fantasy History at Ars Technica

Posted on November 26, 2013 by Michal Necasek

Ars Technica today published an article titled “Half an operating system: The triumph and tragedy of OS/2“. Although very interesting, unfortunately the article to a significant extent engages in what can best be called fantasy history, which causes the text … Continue reading →

Posted in IBM, Microsoft, OS/2 | 52 Comments

More on LOADALL and OS/2

Posted on October 27, 2013 by Michal Necasek

As previously mentioned, IBM’s OS/2 1.0 and 1.1 used the 286 LOADALL instruction, even on 386 and later processors which do not support it. This was typically solved by BIOS emulation. Now there’s more information about how OS/2 uses LOADALL. … Continue reading →

Posted in IBM, Intel, Microsoft | 31 Comments

LOADALL Strikes Again

Posted on October 18, 2013 by Michal Necasek

A minor mystery recently popped up while running IBM’s OS/2 1.1 (1988), the first OS/2 version with the Presentation Manager GUI. While Microsoft’s and IBM’s releases of OS/2 were fully compatible from application perspective, there were differences in the drivers … Continue reading →

Posted in IBM, Intel, Microsoft, OS/2, x86 | 13 Comments

Ctrl-Alt-Del Myths

Posted on October 4, 2013 by Michal Necasek

In a recent interview at Harvard University, Bill Gates claimed (around 16:35 mark) that Windows uses Ctrl-Alt-Del as a logon key combination because “IBM didn’t want to give [Microsoft] a single button”. This statement is curious because it takes several facts … Continue reading →

Posted in Microsoft, PC hardware | 8 Comments

Twenty Years Ago Today…

Posted on July 24, 2013 by Michal Necasek

On July 24th 1993, Microsoft finalized the first release of Windows NT, labeled version 3.1 “to avoid confusion”. This was a big day for Microsoft, although the practical impact on the computer industry was not particularly big, at least not … Continue reading →

Posted in Microsoft, NT | 6 Comments

The Oldest OS/2 Executable In the Wild

Posted on March 22, 2013 by Michal Necasek

While researching the history of Microsoft’s segmented-executable linker originally called LINK4.EXE, I came across an OS/2 executable that was publicly released almost a year before the first OS/2 SDK was shipped, and many months before OS/2 was even announced. In … Continue reading →

Posted in DOS, Microsoft, OS/2 | 16 Comments