Author Archives: Michal Necasek

SC-8820 Gripes

Posted on April 3, 2015 by Michal Necasek

After a long while, I dusted off my Roland SC-8820 sound module which I bought used about 10 years ago. The goal was to drive it from an older PC via MIDI. This turned out to be a lot harder than … Continue reading →

Posted in MIDI, Roland, Sound | 12 Comments

IBM XENIX: One Step Forward, One Step Back

Posted on March 29, 2015 by Michal Necasek

A while ago I wrote about why IBM PC XENIX 1.0 can’t work on any CPU other than a 286. But not content to leave well enough alone, I attempted to patch this version of XENIX so that it would … Continue reading →

Posted in 286, 386, IBM, VirtualBox, Xenix | 5 Comments

The DOS 4.0 Shell Mouse Mystery

Posted on March 21, 2015 by Michal Necasek

Several years ago, I noticed that in some virtual and physical environments, the DOS Shell in both IBM’s and Microsoft’s DOS 4.0x has a very odd glitch: the mouse pointer moves, but does not register any clicks… except on scroll … Continue reading →

Posted in DOS, IBM, PC hardware, PC history | 28 Comments

Do You Know These Peripherals?

Posted on March 18, 2015 by Michal Necasek

After a long pause, here’s another guessing game. Do you recognize the five peripherals below? This should be very easy since the manufacturers’ names are clearly visible, only the model numbers got “lost”. This is all 1980s-1990s hardware from (obviously) … Continue reading →

Posted in MIDI, Roland, Sound, Yamaha | 10 Comments

What Is DXP44Q?

Posted on March 14, 2015 by Michal Necasek

Today I came across a random 1996 vintage ISA sound card (no name, made in China). The only two chips worth noting on the board are an OPTi 82C930A chip and a mysterious DXP44Q—a square chip center left, to the … Continue reading →

Posted in PC hardware, Sound | 12 Comments

Solaris 2.6, 7, and 8 Crashes on Pentium 4 and Later

Posted on February 27, 2015 by Michal Necasek

A blog reader recently pointed to an interesting problem which affects older Solaris releases on certain systems. The symptoms (crash/reboot) may at first glance look like the previously described problem which affected Solaris 2.5.1 and 2.6, but both the cause and … Continue reading →

Posted in Bugs, Debugging, Intel, Solaris | 2 Comments

Digressions

Posted on February 20, 2015 by Michal Necasek

Here’s a little story illustrating the fundamental interconnectedness of all things that I wanted to share… 1) A while ago I started researching the technology of and history behind Yamaha’s OPL2 and OPL3 FM synths (just because I was curious). 2) Sometime … Continue reading →

Posted in Random Thoughts | 9 Comments

ThinkPad 701 Restore Using CF Media

Posted on February 15, 2015 by Michal Necasek

Thanks to a kind reader, the OS/2 Museum obtained a file archive of the ThinkPad 701 recovery CD. The 701C/701CS was also known as Butterfly thanks to its unique folding keyboard. The recovery tool appears to have been designed for … Continue reading →

Posted in IBM, ThinkPad | 23 Comments

Demented Board

Posted on January 31, 2015 by Michal Necasek

Last week I encountered a problem that I have never seen before with a recently acquired Socket 7 motherboard. The board was a Gigabyte GA-586HX (Rev. 1.58), a relatively uninteresting older Socket 7 board based on the well-regarded Intel 430HX … Continue reading →

Posted in Bugs, PC hardware | 14 Comments

Windows 3.0 DR 1.14, February 1989

Posted on January 16, 2015 by Michal Necasek

Another rather interesting software artifact surfaced just recently, after more than 25 years since its release: Windows 3.0 Debug Release 1.14 (further referred to as DR 1.14) from February 1989. This was an alpha version only provided to select ISVs … Continue reading →

Posted in 386, Microsoft, PC history, Windows | 90 Comments