Expanded vs Extended memory, or EMS vs XMS

Expanded vs Extended memory, or EMS vs XMS

DOS veterans may remember messing with expanded and extended memory to get memory above 640K. Here’s what you need to know about expanded vs extended memory, or EMS vs XMS. They are two different approaches to solving the same problem.

Read more

Why did old PCs have a turbo button?

Why did old PCs have a turbo button?

Old PCs, especially PCs from the 1980s to the mid 1990s, have a button with the curious label “Turbo.” On some PCs, a number on the front changes when you push it, or an LED toggles on or off. Why did old PCs have a turbo button?

Turbo buttons are a quirk of old PCs, kind of like their beige color that tends to turn yellow, but it served a functional purpose.

Read more

Why did IBM fail at PCs?

Why did IBM fail at PCs?

If you ask why did IBM fail, I assume you mean why did IBM ultimately fail in the personal computer market. IBM is still in business, after all. But its exit from the PC market after 24 years, including a period of dominance in the 1980s, does seem curious. And it raises another question: What does IBM do now?

I experienced IBM’s fall in this market firsthand. I sold computers at retail in 1994 and 1995. IBM’s computers at that time were no worse than anyone else’s, but I had an extremely difficult time selling them. Many consumers didn’t trust IBM and didn’t want to get somehow locked in. There was nothing wrong with those machines, but it sure was a lot easier to just sell them a Compaq.

Read more

IBM PS/2 vs PC

IBM PS/2 vs PC

The IBM PS/2 line was a fairly radical departure from the older IBM PC line. This was deliberate, as IBM wanted to disrupt the clone industry, which it saw as a threat to its business. Here’s a look back at the IBM PS/2 vs PC, the line it replaced.

IBM succeeded with the PC because it created an ecosystem, not just a PC. IBM’s misstep was creating an open architecture and then trying to close it back up after the fact with the PS/2. In IBM’s defense, it’s not clear whether they knew this at the time. If nothing else, in the case of the IBM PS/2 vs PC, IBM created a classic case study of open architecture vs closed.

Read more

IBM PS/2 series

IBM PS/2 series

The IBM PS/2 line, released April 2, 1987, was IBM’s attempt to reinvigorate its aging personal computer line and fight off cloning. Although the line sold fairly well, it failed to hold off cloning and IBM never regained the market dominance it enjoyed in the first half of the decade.

The IBM PS/2 did offer numerous enhancements over the PC line it replaced, but IBM’s customers came to resent the high price and the perception that IBM was trying to lock out third party peripherals. IBM’s decline was slow, but the PS/2 was the beginning of the end for IBM’s personal computer business.

Read more

Commodore 64 vs Amiga

Commodore 64 vs Amiga

Looking at the Commodore 64 vs Amiga seems a little odd, at least to me. After all, the machines were never intended to be rivals. The Amiga was supposed to succeed the 64. Commodore bought Amiga because they couldn’t make a 64 successor on their own, so they intended for the Amiga to replace it. It didn’t fully succeed, and maybe that’s why the comparison is still interesting.

Looking back, the machines may seem similar today. But in 1985 they sure didn’t.

Read more

Mehdi Ali: Commodore spinmeister

Mehdi Ali: Commodore spinmeister

I found the thumbnail biography of one Mehdi Ali recently. It reads, in part:

“His prior experience includes serving as the President of Commodore International, where he accomplished a major operational turnaround.”

I don’t think he and I share the same definition of “major operational turnaround.”

Read more

Building DOS gaming PCs

Building DOS gaming PCs

The ultimate DOS gaming PC is a topic that I’ve seen come up in forums frequently, and that I’ve been asked directly a number of times. I guess since I published advice on running DOS games on Windows PCs on two continents, people figured I knew something about that. I guess I fooled them!

The trouble is that no single PC can really be the “ultimate” DOS game machine. Well, not if your goal is to be able to optimally run everything from early 1980s titles designed for the original IBM PC up to the last DOS version of Quake. I learned that the hard way in 1995 or 1996, even before Quake existed. Read more

The Post-Dispatch may be giving the wrong idea about the dollar value of vintage computers

Articles like Top 10 collectibles for value, from the Post-Dispatch this week, frequently make me nervous, mostly because of statements like this one:

[D]id you know that computer parts can bring home cash, too?

Statements like that tend to get people’s hopes up way too high. I find the timing interesting though, seeing as a TRS-80 Model 1 sold at a St. Louis estate sale this past weekend. The estate seller’s reaction? “Normally you can’t give that stuff away.”

Read more

IBM PCjr and Tandy 1000

IBM PCjr and Tandy 1000

On January 29, 1984, two computers hit the market. One was Apple’s Macintosh. It needs no introduction. The other was the IBM PCjr. It was a little less successful. We’ll talk about what this has to do with the Tandy 1000 in a minute.

The PCjr is one of the biggest flops in computing history. Few people know much more about it than that. It ended up being an important computer, but it certainly didn’t meet IBM’s expectations. Read more