Category Archives: PC history

FantasyLand on VGA

Posted on April 3, 2022 by Michal Necasek

In 1984, Joel Gould of IBM Cambridge (that is Cambridge, Massachusetts rather than Cambridge, UK) Scientific Center wrote a demo program named FantasyLand. This demo was meant to show off the capabilities of IBM’s brand new Enhanced Graphics Adapter, or … Continue reading →

Posted in IBM, PC hardware, PC history, VGA | 16 Comments

Reconstructing the EGA BIOS

Posted on March 19, 2022 by Michal Necasek

A few weeks ago I had a sudden need to understand certain finer points of the operation of EGA/VGA BIOS. I found common reference materials to be inadequate—they tend to do a good job of documenting the data structures the … Continue reading →

Posted in BIOS, Development, Documentation, Graphics, IBM, PC history | 32 Comments

Learn Something Old Every Day, Part IV: Ctrl+Scroll Lock is Ctrl+Break

Posted on February 26, 2022 by Michal Necasek

The other day I tried running NSNIPES, a multiplayer networked game that came with old versions of NetWare. The game worked fine, but I couldn’t get out of it. Esc did nothing, any “usual” combinations like Alt+X, Alt+Q or similar … Continue reading →

Posted in NetWare, PC architecture, PC history | 3 Comments

Where Did CP852 Come From?

Posted on February 15, 2022 by Michal Necasek

In the 1990s, a lot of my documents were written in code page 852 (CP852), also known as PC Latin 2. This code page is sometimes called “Eastern European”, which is a bit misleading, given that it does not cover … Continue reading →

Posted in DOS, I18N, IBM, Microsoft, OS/2, PC history | 47 Comments

XMVM Surgery

Posted on February 11, 2022 by Michal Necasek

Last week I was prompted to take a look at the Intel Code Builder compiler from 1991, a 32-bit compiler targeting 386 extended DOS and shipping with its own DOS extender. It is what one might call an extremely obscure … Continue reading →

Posted in 386, Development, Intel, PC history, Software Hacks | 10 Comments

Another Trip to Drive Geometry Hell

Posted on January 24, 2022 by Michal Necasek

Recently I took another close look at the IDE.DSK driver in NetWare 3.12. Among other things, I wanted to know how it differs from ISADISK.DSK. On some systems, the two drivers are interchangeable and either will work. But there are … Continue reading →

Posted in IDE, NetWare, PC history | 8 Comments

Another Myth Busted

Posted on January 19, 2022 by Michal Necasek

More than once I came across a story of a heroic MicroPro programmer who in an all-night session managed to port WordStar from CP/M to DOS by patching a single byte. This is how the legend was retold by Joel … Continue reading →

Posted in CP/M, DOS, PC history, WordStar | 5 Comments

Unidentified PC DOS 1.1 Boot Sector Junk Identified

Posted on January 7, 2022 by Michal Necasek

Anyone trying to disassemble the PC DOS 1.1 boot sector soon notices that at offsets 1A3h through 1BEh there is a byte sequence that just does not belong. It appears to be a fragment of code, but it has no … Continue reading →

Posted in Development, DOS, PC history | 24 Comments

First Dual-Channel IDE?

Posted on December 28, 2021 by Michal Necasek

The OS/2 Museum recently came into possession of what may be the first adapter with support for two IDE channels… sort of: The adapter was made by Plus Development Corporation, a subsidiary of the disk maker Quantum. This particular specimen … Continue reading →

Posted in IDE, PC hardware, PC history, Quantum | 29 Comments

The Secret History of ATAPI

Posted on November 24, 2021 by Michal Necasek

The other day I asked myself a seemingly trivial question: What was the first ATAPI CD-ROM drive and when was it available? Given that ATAPI was a major technology which instantly obsoleted all proprietary CD-ROM interfaces and made SCSI much … Continue reading →

Posted in CD-ROM, PC history, Standards, Undocumented | 60 Comments