OS/2 Museum

IBM OS/2 1.0 in a VM

Posted on March 21, 2014 by Michal Necasek

As previously mentioned, IBM’s OS/2 1.0 and 1.1 is extra unfriendly to modern hypervisors. To recap, there is a curious difference between IBM’s and Microsoft’s kernels in OS/2 1.0/1.1 with regard to mode switching.

For reasons that aren’t very clear, IBM’s kernels implement only 286 style mode switching: In order to get from protected back to real mode, the processor is reset and the BIOS told where to resume execution. On the other hand, Microsoft’s kernels have had (faster) 386-specific code ever since the first OS/2 SDK beta from April 1987.

To make matters more interesting, the OS/2 kernel is also famous for using the undocumented LOADALL instruction when running on a 286. Yet IBM’s OS/2 did run on 386 AT clones of the era. How is that possible? Continue reading →

Posted in IBM, Microsoft, OS/2, VirtualBox, Virtualization | 36 Comments

What’s in a Name?

Posted on March 7, 2014 by Michal Necasek

The following four processors are much more similar than one might think:

486 aficionados will recognize the processors made by IBM, ST Microelectronics, and Texas Instruments to be essentially one and the same model—Cyrix 486DX. Continue reading →

Posted in 486, Cyrix | 14 Comments

Surfing Modern Web With Ancient Browsers

Posted on March 4, 2014 by tenox

(note this is a guest post by Tenox)

UPDATE: there is a new version released as a Web Proxy service and available for both Mac OS X and Linux. Read on here…

I spend a fair amount of time working with legacy operating systems. Apart from being obsolete themselves they suffer from a common problem – the web browsers are simply unusable on a present day Internet. You start by getting JavaScript error on google.com and it only gets worse once you go further. Try going to microsoft.com with IE 1.5 or qnx.com with the last version of Voyager. This just doesn’t work. With rapid progression of web standards, the situation will only be getting worse in time. Something had to be done to ease the situation.

Quite a while ago I’ve came across Opera rendering proxy for mobile browsers. This got me thinking. If you could render a web page on a proxy server to a simplified HTML, say 3.x. This would make a lot of web browsers happy. For some unrelated purposes I have been using webkit2png which allows to create a whole web page snapshot in a single png image. Wait… what if such image had an image map of clickable regions pointing to the original links? Maybe… Continue reading →

Posted in Networking | 5 Comments

Kids These Days, Continued

Posted on February 28, 2014 by Michal Necasek

As the OS/2 museum pointed out, many kids these days don’t really know how to properly use floppies. Fortunately, not all is lost and at least some youngsters know exactly what to do with a 3½” diskette.

First, firmly hold the floppy…

Continue reading →

Posted in Floppies | 6 Comments

Soyo SY-4SAW2 Notes

Posted on February 26, 2014 by Michal Necasek

Following is a list of notes describing several less-than-obvious features and characteristics of the Soyo SY-4SAW2 486 VIP motherboard. This is a latter-day 486 board based on the SiS 496/497 chipset, notable for PS/2 mouse support and the ability to use just about any CPU compatible with Socket 3.

Most of these characteristics and limitations are a direct consequence of the use of the SiS 85C496/497 chipset and the way said chipset is configured in the 4SAW2 board. Continue reading →

Posted in 486, PC hardware | 8 Comments

Untested Error Paths

Posted on February 20, 2014 by Michal Necasek

About a week ago I revived an old Sony VAIO laptop (model PCG-R505TS) that hadn’t been used for a few years. It had lost CMOS contents so I had to re-enter the date and adjust a few BIOS settings.

The laptop had XP SP1 installed, which I successfully updated to SP3. Too lazy to use the built-in wired Ethernet, I plugged in a Belkin wireless PC Card instead. Windows Update successfully installed the usual bazillion of updates and the laptop was running stable, yet I was experiencing inexplicable errors and odd behavior.

Some web sites reported certificate errors, which I (erroneously, it turned out) ascribed to out of date root certificates on the system. Updated root certificates are available on Windows Update, but that’s where another strange problem hit: For whatever reason, the root certificates are an optional update and as such, require Windows to be validated (the infamous WGA). Windows Update offered to validate my copy of Windows, but the validation process eventually landed on an empty web page with no error message whatsoever. The validation did not really fail (declaring my setup a pirate copy), it just did nothing. What was I doing that was so unusual to trigger some untested error path?

Continue reading →

Posted in PC hardware, Windows | 3 Comments

Soyo 4SAW2: Why So Slow?

Posted on February 15, 2014 by Michal Necasek

Continuing to go through my junk pile, I unearthed a Soyo SY-4SAW2 motherboard. This is a late 1995 vintage 486 ISA/VLB/PCI motherboard with a SiS 85C496/497 chipset. It’s a classic Baby AT board with an AT keyboard connector, although it does support PS/2 mice (which is rather nice).

The board works well enough, but somehow it’s just… slow. SYSINFO from Norton Utilities 8.0 shows a score of 131 with an Intel DX4 processor running at 100MHz (33.3MHz x 3). At 75MHz (25MHz x 3), the same processor scores only 99.2. Other benchmarks fare similarly.

Yet the exact same CPU plugged into an Alaris Cougar ISA/VLB board, about a year older and using an OPTi chipset, scores 197.5 at 100MHz and 148.9 at 75MHz in SYSINFO. (And in case someone asks how I ran a 3.3V DX4 processor in the 5V-only Cougar board, I used an AMD voltage converter.) That is, the Intel DX4 processor running at 75MHz in the Alaris board scores better than when running at 100MHz in the Soyo board. Something is clearly amiss. Continue reading →

Posted in PC hardware | 21 Comments

Butterfly Conservation

Posted on February 8, 2014 by Michal Necasek

The OS/2 Museum recently acquired one of the famous IBM 701 ThinkPads, commonly nicknamed “Butterfly” thanks to the fold-out keyboard. Unfortunately, the unit suffered a fate common to many old ThinkPads—battery leakage.

The unit would power on, but it had serious problems. The CMOS battery was dead, causing errors on each startup, and the graphics chip was flaky, fairly often resulting in completely corrupted characters in text modes and very strange looking graphics modes. Worst of all, the unit was very unstable, sometimes not even making it past POST and never staying up for more than a few minutes. Continue reading →

Posted in PC hardware, ThinkPad | 3 Comments

Have You Ever Used One of These?

Posted on January 31, 2014 by Michal Necasek

Still on the theme of unusual hardware… in my junk pile there’s one of these rather special little parts:

As the label on the PCB says, this is a 486 pod for a Periscope IV debugger. The Periscope Company of Atlanta, GA was a respected supplier of hardware-assisted debuggers in the late 1980s and early 1990s. Continue reading →

Posted in Debugging, PC hardware | 38 Comments

Early PCI Board

Posted on January 28, 2014 by Michal Necasek

Since some of this blog’s readers are very good at recognizing obscure hardware, I thought I’d post photos of one more somewhat exotic graphics card:

This board was one of the early PCI graphics adapters. It’s old enough that it doesn’t use the standardized PCI class ID. It’s based on the S3 928P chip and equipped with 1MB video memory. Continue reading →

Posted in Graphics, PC hardware | 27 Comments