Monthly Archives: August 2014

OS/2 Kernel Debugger and MVDM Interrupts

While working on an unrelated problem, I noticed a strange behavior of one of my OS/2 VMs running OS/2 Warp 4.52. To cut a long story short, if an unhandled floating-point exception occurred in a DOS window (VDM, or Virtual … Continue reading

Posted in Bugs, Debugging, OS/2 | 11 Comments

IBM Blue Lightning: World’s Fastest 386?

One of the OS/2 Museum’s vintage boards is a genuine Made in U.S.A. Alaris Cougar. These boards were produced by IBM for Alaris and are a bit unusual: There’s a small IBM DLC3 processor in plastic package soldered on board, … Continue reading

Posted in 386, IBM, Intel, PC hardware, PC history | 31 Comments

Semantic Differences, Microsoft v. Microsoft

While comparing the behavior of various versions of old Microsoft C compilers, I tried building a trivial hello-world type program with CL.EXE from Microsoft C/C++ 7.0 (March 1992) running on top of a 32-bit Windows Server 2003. This seemingly trivial … Continue reading

Posted in DOS, Microsoft, Virtualization | 6 Comments

NT Video Miniport for VirtualBox, With Source Code

Upon reader request, the OS/2 Museum is publishing the source code to the NT video miniport driver for VirtualBox. To recap, this is a NT video miniport which allows 32-bit NT versions to use high-resolution graphics modes in a VirtualBox VM. The … Continue reading

Posted in Graphics, NT, Source code, VirtualBox | 4 Comments