Category Archives: Windows

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 | 52 Comments

A House of Cards

Posted on December 30, 2022 by Michal Necasek

As one step in the development of the Windows 3.x/2.x display driver, I needed to replace a BIOS INT 10h call to set the video mode with a “native” mode set code going directly to the (virtual) hardware registers. One … Continue reading →

Posted in Bugs, Development, Microsoft, Windows | 49 Comments

Win16 Retro Development

Posted on December 20, 2022 by Michal Necasek

Several months ago I had a go at producing a high resolution 256-color driver for Windows 3.1. The effort was successful but is not yet complete. Along the way I re-learned many things I had forgotten, and learned several new … Continue reading →

Posted in Debugging, Development, Microsoft, Windows | 25 Comments

Antique Display Driving

Posted on July 29, 2022 by Michal Necasek

Here’s a preview of something I’ve been slowly working on, bit by bit: That screenshot surely looks a little funny. That’s because it is Windows 1.04 running with a heavily modified 256-color Windows 3.x display driver, using resources from a … Continue reading →

Posted in Development, Microsoft, Windows | 35 Comments

Learn Something Old Every Day, Part VI: Backward Buffer Overwrite

Posted on July 13, 2022 by Michal Necasek

A few days ago I spent far too much time debugging a largish piece of 16-bit Windows code written in assembler. I found a scenario where (fortunately fairly reproducibly) Windows crashed because the internal state of a DLL got corrupted. … Continue reading →

Posted in Bugs, Development, Windows | 24 Comments

FasterModeSwitch: Is It Really?

Posted on October 31, 2018 by Michal Necasek

Short answer: Yes. Before launching into the long answer, let’s recap what it even is. FasterModeSwitch is a SYSTEM.INI setting in Windows 3.1 which applies only to Standard (286) mode and can therefore be found in the [standard] section of … Continue reading →

Posted in 286, BIOS, Microsoft, Windows | 10 Comments

Didn’t Expect That to Work

Posted on October 22, 2018 by Michal Necasek

Once the ThinkPad T43p with a bad fan was in working shape again, I restored the preloaded software on it. Which meant Windows XP (this is a system from 2005). It didn’t take long for me to establish that XP … Continue reading →

Posted in ThinkPad, Windows | 22 Comments

Crazy World

Posted on October 17, 2018 by Michal Necasek

After I successfully upgraded two Windows 10 VMs to the 1809 release at the beginning of October, I tried to do the same with more VMs and an actual laptop this week. But I couldn’t, no update was offered. While … Continue reading →

Posted in Bugs, Microsoft, Random Thoughts, Windows | 9 Comments

Three Weeks

Posted on July 27, 2018 by Michal Necasek

I happen to own several old laptops, now about 10 years old, that had the misfortune of being delivered with a Windows Vista license and matching Windows Vista OEM installations on their recovery partitions/media. About a year ago, I noticed … Continue reading →

Posted in Bugs, Microsoft, Windows | 27 Comments

Alt Insanity

Posted on November 17, 2016 by Michal Necasek

Several times, a question came up how to synthesize keyboard input to a remote system given a text string. The remote system is typically but not necessarily a VM. That sounds like something which should be trivial, yet it is anything but. … Continue reading →

Posted in Virtualization, Windows | 14 Comments