Retro Computing Archives

Did Microsoft steal DOS from CP/M?

Dave Farquhar Retro Computing August 8, 2016May 3, 2026computer software, Digital Research, Gary Kildall, IBM, intel, Jerry Pournelle, podcast, SCO

Did Microsoft steal DOS from CP/M? There’s $100,000 in it for you if you can prove they did.

Digital forensics consultant Bob Zeidman still says no. I’ve written about him before. But the rumors persist, hence the reward. So how would one go about claiming it?

Start with what we know.

Dave Farquhar

David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.

dfarq.homeip.net

Gary Kildall’s memoirs released

Dave Farquhar Retro Computing August 4, 2016November 25, 2018Gary Kildall

Gary Kildall’s memoirs are legendary vaporware. Until now. Today, the Computer History Museum released 79 pages of it. What was released today isn’t the whole manuscript. But it’s better than what we had yesterday.

Gary Kildall is one of the unsung heroes of early computing. As such, he’s one of my favorite people to write about.

Late in his life, he started to write a memoir. I’ve only had a chance to read parts of the first two chapters, but they explain the man and his motives. It’s not the whole manuscript, and some people aren’t happy about that. But it’s better than what we had yesterday.

Most of what exists of computing history came from the victors’ point of view. Gary Kildall wasn’t one of the winners. But without his contributions, the winners wouldn’t have had much to build on.

Maybe someday Gary Kildall will get his due. Releasing his story in his own words is a start.

Undoubtedly I will have more to say after I read all 79 pages myself. But this release is too important not to mention.

Dave Farquhar

dfarq.homeip.net

What did a Commodore 64 cost?

Dave Farquhar Retro Computing August 3, 2016May 13, 2023

It’s pretty widely known that the Commodore 64 was the first 64K computer to sell for under $600. But what did a Commodore 64 cost over time? And what was the exact Commodore 64 launch price?

Dave Farquhar

dfarq.homeip.net

How to load Commodore 64 games

Dave Farquhar Retro Computing July 22, 2016April 16, 2024commodore, commodore 64

You had to know a command to load Commodore 64 games, because, unlike many other computers of its day, it didn’t automatically boot game disks when you turned it on.

Things worked best if you followed a process.

Dave Farquhar

dfarq.homeip.net

The first successful home computer: Commodore VIC-20

Dave Farquhar Retro Computing June 24, 2016December 27, 2025apple, apple ii, CBM, commodore, Commodore 16, jack tramiel

What was the first successful home computer? Some people would argue it was the Apple II, the TRS-80 Model I, or perhaps even the Apple I. But I argue it was Commodore’s VIC-20.

Maybe I’m biased. I was a Commodore fan growing up and my first experience with a computer was probably on a VIC-20. But I think I can make a case.

Dave Farquhar

dfarq.homeip.net

The silver label Commodore 64

Dave Farquhar Retro Computing June 14, 2016June 16, 2024

The most valuable examples of the Commodore 64, generally speaking, are the early variants that have silver labels across the top. The silver label Commodore 64 is the earliest, most expensive example of the venerable machine.

In all, Commodore produced about 80,000 of these machines. That compares to several million of the most common variants. That alone makes early models relatively rare. When you do find one, there’s a fairly good chance it’s not 100% original. The silver label Commodore 64 is the equivalent of the Atari 2600 heavy sixer, but more rare.

Dave Farquhar

dfarq.homeip.net

Origin of CP/M’s PIP command

Dave Farquhar Retro Computing June 8, 2016November 26, 2018command prompt, commodore, commodore 128, DEC, Digital Equipment Corporation, Gary Kildall, PIP, syntax, unix

CP/M was, as you probably know, the first popular microcomputer operating system. It was good but imperfect, and its cryptic command for copying files, PIP, is often cited as an example. Copy makes sense. Even the Unix equivalent, cp, makes sense–it’s copy without the vowels. But what does PIP mean? What’s the origin of CP/M’s PIP command?

Dave Farquhar

dfarq.homeip.net

Commodore 64 vs 128

Dave Farquhar Retro Computing May 19, 2016October 26, 20221541, 1571, 1980s, 6502, amiga, apple, apple ii, c64, commodore, commodore 128, commodore 64, tape drive

Commodore introduced the Commodore 128 in 1985 as an upgrade path from the Commodore 64, the most popular model of computer of all time. The 128 addressed the 64’s biggest shortcomings while remaining mostly compatible with its hardware and software. That makes the Commodore 64 vs 128 a natural comparison, even more natural than comparing the 64 with the VIC-20.

The Commodore 128 was an extension of the Commodore 64, with more memory, a faster disk drive, a faster CPU, and 80-column video. It also featured a very high degree of compatibility, which helped both machines sell better.

Dave Farquhar

dfarq.homeip.net

Commodore 64 vs 64c

Dave Farquhar Retro Computing May 9, 2016June 2, 20241541, 1980s, 1990s, Bil Herd, c64, commodore, commodore 64, IBM, Personal Computer, Tandy, tandy 1000

The Commodore 64 went through a number of revisions throughout its long life. The most outwardly visible of those revisions was the transition from the tan, boxy C-64 to the thinner, lighter-colored 64c. If you’e wondering about the Commodore 64 vs 64c, here’s what you need to know.

Dave Farquhar

dfarq.homeip.net

C64 vs Apple II

Dave Farquhar Retro Computing May 5, 2016September 15, 20251980s, 1990s, 6502, apple ii, commodore 64

The C64 vs Apple II was perhaps the most epic battle of the 8-bit era. Both companies sold millions of machines, yet both nearly went out of business in the process.

Comparing the two machines with the largest software libraries of the 8-bit era is a bit difficult, but that’s what makes it fun. The two machines are similar enough that some people ask if the Commodore 64 was an Apple product. The answer is no.

As a weird aside, it was possible, with a Mimic Systems Spartan, to turn a C-64 into an Apple II. Not many did, but the reason why is another story.

Dave Farquhar

dfarq.homeip.net

The Silicon Underground

Retro Computing

Did Microsoft steal DOS from CP/M?

Gary Kildall’s memoirs released

What did a Commodore 64 cost?

How to load Commodore 64 games

The first successful home computer: Commodore VIC-20

Read more

The silver label Commodore 64

Origin of CP/M’s PIP command

Commodore 64 vs 128

Commodore 64 vs 64c

C64 vs Apple II