Category Archives: IBM

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

The Carolina Mystery

Posted on October 21, 2013 by Michal Necasek

On the weekend I decided to examine my old PowerPC 604 system. The case is from a RS/6000 type 7248, but the actual system board is from a Power Series 830. This is the famous Carolina board (or “planar” in … Continue reading →

Posted in IBM, PowerPC | 6 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 | 11 Comments

IBM ThinkPad Power Series 850

Posted on October 14, 2013 by Michal Necasek

In the mid-1990s, IBM and Motorola unsuccessfully tried to create a new personal computer platform built around PowerPC RISC processors. Apple was initially a member of the alliance called AIM (Apple/IBM/Motorola) and used PowerPC processors in its own Macintosh systems … Continue reading →

Posted in IBM, PowerPC | 40 Comments

OS/2 on ThinkPad 850

Posted on September 27, 2013 by Michal Necasek

The ThinkPad 850 was no ordinary ThinkPad. It was IBM’s high-end portable multimedia workstation, built around a 100MHz PowerPC 603e processor, with a list price of $12,399 (February 1996). The ThinkPad 850 was originally slated (see IBM announcement letter 195-176) to … Continue reading →

Posted in IBM, OS/2, PowerPC | 18 Comments

The XDF Diskette Format

Posted on August 30, 2013 by Michal Necasek

In 1994, IBM started shipping software with support for XDF, or eXtended Density Format, first in OS/2 Warp and a few months later in PC DOS 7.0. Some of IBM’s software packages were also distributed on XDF diskettes. XDF allowed … Continue reading →

Posted in Floppies, IBM | 24 Comments

Why Won’t IBM’s MSPS201.SYS Load?

Posted on August 23, 2013 by Michal Necasek

Recently a minor mystery resurfaced. When IBM’s OS/2 1.2 SE is installed on any “normal” system (either physical or virtual) and the PS/2 mouse driver is installed (the typical choice), the mouse won’t work: The MSPS201.SYS driver is intended for … Continue reading →

Posted in IBM, OS/2 | 8 Comments

Detecting Floppy Drives and Media

Posted on August 14, 2013 by Michal Necasek

Detecting floppy drive types and installed media is a far trickier topic than it should have been. In the ideal world, software could determine how many floppy drives are attached, what their capabilities are, and what media is installed in … Continue reading →

Posted in Floppies, IBM, PC hardware | 18 Comments

DOS Goodies at bitsavers.org

Posted on May 27, 2013 by Michal Necasek

The excellent bitsavers.org last week uploaded scans of several IBM Personal Computer DOS manuals. Included are the manuals for DOS 1.0 (1982), 1.1, and 2.0, a preliminary technical reference for DOS 3.1, the DOS 3.1 user’s reference manual, and DOS … Continue reading →

Posted in DOS, IBM | 1 Comment

ISA bus 8514/A?

Posted on May 24, 2013 by Michal Necasek

During the development of the 8514/A, IBM clearly had ISA-based adapters. A proof of this may be found in the source code for the Windows 2.x setup program (part of the Binary Adaptation Kit, or BAK), which among other things … Continue reading →

Posted in Graphics, IBM, PC hardware, Windows | 7 Comments