Retro Computing Archives

Thank you, Jerry Pournelle

Dave Farquhar Retro Computing September 9, 2017Jerry Pournelle, journalism

Longtime computer columnist and science fiction author Jerry Pournelle died on Sept 8, 2017. I count Dr. Pournelle as one of my influences.

I was never a big sci-fi fan, so I’ve never read any of his novels. I really enjoyed his computer journalism, however. He was a tech curmudgeon, and he was blunt, but frequently that was what we needed, especially in those early years when computers didn’t work as well as they do today.

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.

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Commodore RAM expansion units

Dave Farquhar Retro Computing August 25, 2017August 24, 20241541, 1980s, 1990s, 6502, commodore, IBM, quantumlink, ram disk

The 6502-family CPUs in Commodore 8-bit computers famously used 64K of RAM at a time. But in 1985, Commodore introduced a cartridge that added up to 512K of RAM to the 128. Commodore followed up soon after with a 256K cartridge for the 64. How did Commodore RAM expansion units work?

Dave Farquhar

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What is the purpose of a screen saver?

Dave Farquhar Retro Computing August 15, 2017December 16, 20201990s, atari, best buy, blank screen, malware, spyware

What is the purpose of a screen saver? Screen savers served both a technical and a marketing purpose. From a technical perspective, the purpose of a screen saver was to keep an image from permanently being engraved in a CRT-based monitor’s phosphors. But it wasn’t long before screen savers started serving a vanity or entertainment purpose.

Dave Farquhar

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Commodore computer models

Dave Farquhar Retro Computing August 14, 2017June 5, 2026

The Commodore 64 is by far the most famous and successful computer Commodore ever made. But there were numerous Commodore computer models over the years. Some were also successful. Some were complete flops. Overall Commodore had a good 18-year run, but it could have been so much longer and better.

Let’s take a walk through the Commodore computer models from the beginning in 1976 to the bitter end in 1994.

Dave Farquhar

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Expanded vs Extended memory, or EMS vs XMS

Dave Farquhar Retro Computing August 11, 2017October 5, 2019Bill Gates, intel, memory slots, XT

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.

Dave Farquhar

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Commodore 64 Z80 cartridge

Dave Farquhar Retro Computing August 9, 2017June 1, 20261541, 1980s, 6502, apple, apple ii, commodore, commodore 64, intel, MOS, spartan

One of the most popular add-ons for an Apple II added CP/M compatibility. So I guess it should be no surprise that Commodore tried the same thing. But the Commodore 64 CP/M operating system and the associate Commodore 64 Z80 cartridge was a flop. Why?

Dave Farquhar

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Why did old PCs have a turbo button?

Dave Farquhar Retro Computing August 1, 2017March 25, 20241980s, 1990s, benchmark, compaq, IBM, XT

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.

Dave Farquhar

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90s computer brands

Dave Farquhar Retro Computing July 27, 2017July 11, 2025

Some 90s computer brands are the same as today, but a lot more companies played in the field than now. Profit margins were higher then, so industry consolidation wasn’t the matter of survival that it is now. The most popular computer brands of today were among the most popular brands in the 90s, but some popular 1990s computers no longer exist in any form.

Here’s a look back at some of the brands of old, including some famous PC brands, some not-so-famous, and some notorious. The 1990s were certainly a make or break time for many of them, arguably just as volatile as the merciless 1980s had been.

Dave Farquhar

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Commodore 256: The 8-bit that never was

Dave Farquhar Retro Computing July 21, 2017June 5, 20261980s, amiga, CBM, commodore, commodore 64, DEC, IBM, IRA

In 1985, Commodore followed up on its best selling Commodore 64 with a model with twice as much memory. The design of the 128 offered the possibility of following up with a Commodore 256. It never happened. Instead, Commodore moved on from 8-bit machines after the 128. Here’s why.

Dave Farquhar

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Disadvantages of the 8086 microprocessor

Dave Farquhar Hardware, Retro Computing July 11, 2017August 11, 20176502, amd, apple, Apple Lisa, DEC, IBM, intel, MOS, motorola, x86

An 8086-series microprocessor, the 8088, powered the original IBM PC. Its direct descendants power PCs to this day. Not only that, they power modern Macs too. This was always controversial, especially running Mac OS on Intel chips. Why? What are the disadvantages of the 8086 microprocessor?

Dave Farquhar

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