Category Archives: PC history

1989 Networking: NetWare 386

Posted on July 20, 2024 by Michal Necasek

Thanks to the recent warez mega dump, another long lost gem has come to light: NetWare 386, also known as NetWare 3.0. In September 1989, Novell released NetWare 386 V3.0, the first in a long line of 32-bit network operating … Continue reading →

Posted in 386, NetWare, Networking, Novell, PC history | 22 Comments

Who Knew What When

Posted on June 28, 2024 by Michal Necasek

When Microsoft released the unique early beta build of Multitasking DOS 4, I quickly found out that it does not run in VirtualBox: This was a bit of a surprise, because the more-or-less released versions of Multitasking DOS 4 from … Continue reading →

Posted in 286, DOS, IBM, Microsoft, PC architecture, PC history, VirtualBox | 26 Comments

The Future That Never Was

Posted on March 4, 2024 by Michal Necasek

Microsoft OS/2 2.0 SDK Pre-Release 2, June 1990 In 1990, the strategic PC operating system of Microsoft and IBM was not DOS, not Windows, but OS/2. The first 16-bit OS/2 was initially released in 1987 with a reduced feature set, … Continue reading →

Posted in 386, IBM, LAN Manager, Microsoft, OS/2, PC history, Pre-release | 76 Comments

Tarbell to Cromemco

Posted on January 23, 2024 by Michal Necasek

While playing around with old versions of 86-DOS, I came across a disk image of 86-DOS 1.14. I ran the older 86-DOS versions in the SIMH simulator which can emulate the Cromemco disk controller supported by 86-DOS. Unfortunately the 86-DOS … Continue reading →

Posted in Development, DOS, PC history | 16 Comments

86-DOS Revisited

Posted on January 15, 2024 by Michal Necasek

At the end of December 2023, several disk images of very old versions of Seattle Computer Products 86-DOS unexpectedly turned up. This includes previously unseen releases of 86-DOS version 0.11 and 0.34 (going by the version number in the 86-DOS … Continue reading →

Posted in DOS, PC history | 24 Comments

VDS: Borne out of Necessity

Posted on October 5, 2023 by Michal Necasek

In July 1990, Microsoft released a specification for Virtual DMA Services, or VDS. This happened soon after the release of Windows 3.0, one of the first (though not the first) providers of VDS. The VDS specification was designed for writers … Continue reading →

Posted in 386, Documentation, Microsoft, PC history, Windows | 10 Comments

First ROM Shadowing

Posted on April 21, 2023 by Michal Necasek

The other day I was asked an interesting question: What was the first BIOS with support for ROM shadowing? In the 1990s, ROM shadowing was common, at first as a pure performance enhancement and later as a functional requirement; newer … Continue reading →

Posted in C&T, Compaq, IBM, PC architecture, PC history | 55 Comments

Windows 3.x VDDVGA

Posted on January 23, 2023 by Michal Necasek

While working on my Windows 3.x display driver, I ran into a vexing problem. In Windows 3.1 running in Enhanced 386 mode, I could start a DOS session and switch it to a window. But an attempt to set a … Continue reading →

Posted in 386, Development, Documentation, Graphics, PC history, Windows | 59 Comments

Learn Something Old Every Day, Part VII: 8087 Intricacies

Posted on January 23, 2023 by Michal Necasek

The other day I investigated a report that a C runtime library modification causes programs to hang on a classic IBM 5150 PC with no math coprocessor. The runtime originally contained two separate routines, one to detect the presence of … Continue reading →

Posted in 8086/8088, Development, IBM, Intel, PC history, x87 | 10 Comments

PC Disk Sector Sizes and Booting

Posted on October 26, 2022 by Michal Necasek

Everyone knows that the IBM PC established 512-byte sectors on floppies and hard disks as the standard, which survived for several decades until the advent of “native” 4K-sector drives. Of course what “everyone knows” is not necessarily the whole story. … Continue reading →

Posted in BIOS, DOS, IBM, PC history, Storage | 15 Comments