My junk pile turned out to contain another board by Vermont Microsystems, Inc. (VMI), probably no less exotic than the mystery board.
This one is a Microchannel board built around an Intel 82786. An in this case, VMI was kind enough to etch their name on the PCB, complete with the model name—Page Manager 100. Continue reading
While cataloging my junk pile, I came across two graphics cards that I could not identify. Both are high-end ISA graphics accelerators from the early 1990s and both utilize Texas Instruments GPUs (long before the term “GPU” was first used, but very appropriate).
The first card was clearly made by SPEA (that is, SPEA Software AG), a German company known for its high-end graphics card. Based on the chip markings, the card must have been manufactured in the second half of 1991.
The site has been unavailable for a while because some creative person or persons decided to use it for sending out spam and setting up a beautifully crafted facsimile of PayPal. It appears that a vulnerability in an old WordPress version was exploited some time ago (several months ago at least); for a while, nothing more happened, but on Dec 31st the attacker(s) started uploading foreign content to the site.
Part of the problem is that WordPress updates do not delete old unused files. In this case, the old and no longer used ‘default’ theme was somehow modified and then used as a backdoor. Because WordPress updates neither delete the unused scripts nor overwrite them, malicious PHP scripts hung around for at least a few months. Learn something new every day…
Let’s hope the problem is now resolved and the site will stay up for a while.
A minor mystery recently surfaced while analyzing DOS boot sectors. DOS uses several criteria when deciding whether a boot sector contains a valid BPB, and one of the criteria is (oddly enough) checking whether the first two bytes of the sector contain a jump instruction, which then presumably skips over the BPB. The MSDISK.INC module in the MS-DOS 3.21 OAK is a good example. The opcodes considered valid are EBh (JMP short), E9h (JMP), or 69h. Wait, an IMUL instruction? Well, no, that’s not what the comment in the source code says:
cmp byte ptr cs:[DiskSector],069H ; Is it a direct jump? je Check_Signature ; don't need to find a NOP cmp byte ptr cs:[DiskSector],0E9H ; DOS 2.0 jump? je Check_Signature ; no need for NOP cmp byte ptr cs:[DiskSector],0EBH ; How about a short jump. jne BadDisk
The problem is that 69h is not a documented 8086 instruction. It’s an IMUL opcode on 80186 and later, but that seems highly implausible. Besides, the comment clearly says it’s a jump.
Since the undocumented 8086 opcodes are, well, undocumented, could 69h possibly behave like a jump on an 8088/8086 processor? A very good question, with remarkably few answers. One might think that in the hacker culture surrounding early PCs, it would be inevitable that someone would find out what the undocumented instructions really do. But that doesn’t appear to be the case. A fairly exhaustive search turned up nothing, even in books like Undocumented PC (Frank van Gilluwe) which devote significant space to undocumented instructions. It still seems that someone, somewhere must have published something…
A quick look at several emulators turned up nothing either. Fortunately, Raúl Gutiérrez Sanz had a genuine 8088 and enough determination to find out what the undocumented opcodes really do. Continue reading
With VirtualBox 4.3, it is possible to install the oldest known pre-release of Windows NT directly from CD, the way Microsoft intended. This is the Fall ’91 Comdex preview which only supported the x86 architecture and a very short list of hardware devices. The pre-release was available only on CD-ROM and although it was possible to install it more or less manually from DOS, there was a graphical installer on the CD-ROM.
However, the hardware support being as limited as it was, the only supported storage controller was Adaptec AHA-1540 or compatible with a SCSI CD-ROM attached. Fortunately this is adequately emulated by the BusLogic SCSI HBA device in VirtualBox.
I recently tried to revive an old ThinkPad 600 (with a 300 MHz mobile Pentium II processor). The system wouldn’t boot up and reported errors (173, 163) which are usually a good indication of a dead CMOS battery. In a 15-year old system, that’s not particularly surprising.
So I opened the memory cover on the bottom of the laptop, removed the CMOS battery from its housing, and pulled on the cable… only to break off the connector from the board instead of just unplugging the wires.
Unfortunately the CMOS battery connector is located right under the shell and can’t be re-attached without more or less completely dismantling the entire laptop, which I proceeded to do. Continue reading
Ars Technica today published an article titled “Half an operating system: The triumph and tragedy of OS/2“. Although very interesting, unfortunately the article to a significant extent engages in what can best be called fantasy history, which causes the text to contradict itself. And while it attempts to present a coherent view of the history of OS/2, the article is more a hodgepodge of facts/products/trends (PS/2, NT, PowerPC) picked at random to support an argument.
It also presents the old “geniuses at Microsoft vs. dumb IBM” story which is increasingly difficult to justify as time marches on. IBM is the bad guy, overly bureaucratic and incompetent. Yet listening to old IBMers a somewhat different picture emerges, with Microsoft being a disorganized, sloppy company producing poorly documented and buggy software. As always, there’s some truth to both sides of the story.
Let’s start with some of the inaccuracies. When OS/2 was conceived and designed, it wasn’t called OS/2 at all. In fact there is no known evidence that the name OS/2 existed before 1987. The name OS/2 had a lot to do with PS/2, but the OS itself not so much. Continue reading
An earlier article about PowerPC-based ThinkPad 850 mentioned that the 850 was a close cousin of x86-based ThinkPads of the era. The OS/2 Museum now takes a look at one of those laptops, and interesting laptop in its own right: the ThinkPad 755CD.
The 755CD’s claim to fame is the fact that it was the first-ever laptop equipped with a built-in CD-ROM drive. In October 1994, a CD-ROM reader was common but not quite standard equipment for desktop computers, and portables by definition only came with a floppy drive. The 755CD flipped things around and came only with a built-in CD-ROM drive, although it could be swapped out for a floppy drive which used the same UltraBay connector. Continue reading
A few weeks ago I needed a 3Com 3C589 PCMCIA network card to run Solaris on a ThinkPad Power Series 850. The Solaris PowerPC HCL only listed 3C589 and 3C589B as supported models (and no other network adapters were listed at all), so I went looking for one of those old cards.
Of course eBay was full of newer 3C589D and 3C589E (Megahertz) variants, but I wasn’t sure those would work with Solaris. In the end I found a 3C589B with manual, driver floppy, and whopping two dongles. What could possibly go wrong?
Once the package arrived, I discovered that while the PMCIA adapter appeared to be working fine, neither of the dongles did. It was possible to plug the dongles into the card and some LEDs might blink, but no link was ever detected. Both dongles were also suspiciously loose. The short story was that while Solaris detected and initialized the card just fine, I was no closer to having a functioning network connection. Continue reading
Note: Most of the following information does not apply to any Lenovo-made ThinkPads or even IBM-made ThinkPads manufactured after circa 1999. If you have one of those laptops protected with an unknown password, please look elsewhere.
Imagine you bought, found, or were given an old ThinkPad. The hardware has very little value as such, but for anyone interested in the history of PC computing, it may be a valuable system nonetheless. These systems tend to have been reasonably well built and are fairly likely to function more or less 100% even after all this time.
If the system is 15-20 years old, chances are the CMOS battery is dead. That would normally not pose any serious difficulty, unless the previous owner was slightly paranoid and set a supervisor password, also called Privileged Access Password or PAP. You will only get as far as this:
The PAP is bad news for two reasons: The original owner probably forgot the password or cannot be contacted at all (might easily be dead!), and the IBM engineers weren’t stupid when they designed the PAP. Continue reading
