Retro Computing Archives

Retrobright with sunlight and no chemicals

Dave Farquhar Retro Computing April 5, 2021October 4, 2021

I heard earlier this year that you can retrobright without chemicals, using only sunlight. I haven’t heard of a lot of people trying it. But I had a yellowed disk drive, and it’s summertime, so I decided to give it a shot.

A few people experimented with retrobright without chemicals in 2019, then the idea kind of faded away. I decided to try it, and found it works surprisingly well.

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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Amstrad PCs: The PC1512 and PC1640

Dave Farquhar Retro Computing February 25, 2021July 27, 2022

The Amstrad PC1512 and PC1640 were inexpensive Korean-made PCs that took Europe by storm in the mid 1980s. Amstrad was the UK’s largest computer maker, and it hoped to replicate that success in the United States as well. Here’s an overview of those machines, and why that effort was less than an overwhelming success.

Dave Farquhar

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FPGA vs retro hardware

Dave Farquhar Retro Computing February 24, 2021February 19, 2025

My roundup of Commodore motherboards turned up on a vintage computer discussion board. A minor aside that I mentioned in passing turned into a major topic of discussion. And then the conversation turned in an entirely different direction. What about going with an FPGA solution, rather than vintage hardware? With an FPGA approach you can be certain you’re getting what you want. But what are the drawbacks of FPGA vs retro hardware, if any?

A purist will object to modern FPGA approaches, usually for more than one reason. But there can be practical advantages to an FPGA solution, and it’s also possible to blend it with a more traditional approach.

Dave Farquhar

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Monitor for a Commodore VIC-20

Dave Farquhar Retro Computing February 22, 2021December 19, 2025

Someone asked in a vintage computer forum recently what the correct monitor would be to use with a VIC-20. Commodore never sold a white monitor the same color as the VIC. Its first color monitor was the 1701, which matched the C-64. If you want a period correct Commodore VIC-20 monitor, you have a couple of options. If you want a holy grail story, the matching monitor for the VIC-20 is a good one.

Commodore cancelled the VIC-1510 monitor for the VIC-20. But there were some third party monitors from the 1980s that look the part.

Dave Farquhar

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The killer POKE for the Commodore PET

Dave Farquhar Retro Computing February 9, 2021March 20, 2025

When I was a kid, computer science textbooks taught a language called Basic. They explained various commands, including POKE, which changed values in memory, or on a chip register. The books went out of their way to explain that you can’t harm a computer with a command, even a POKE. But it turned out there was an exception–the infamous POKE 59458,62 on the Commodore PET. The infamous killer POKE.

The killer POKE, POKE 59458,62, sped up the Commodore PET 2001’s video output at the expense of degrading the video quality. The tradeoff seemed worth it, except it could damage the machine over time.

Dave Farquhar

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IBM PS/Valuepoint

Dave Farquhar Retro Computing January 21, 2021October 4, 2021

The IBM PS/Valuepoint was IBM’s attempt to address public objections to the IBM PS/2 series. Introduced in October 1992, they were the most clone-like IBM business desktops since the IBM PC/AT. As the name suggests, they were designed to be price competitive with the higher-end PC clones like a Compaq Deskpro. IBM sold them alongside the PS/1 and PS/2.

Dave Farquhar

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Is the Commodore 128 power supply safe to use?

Dave Farquhar Retro Computing December 30, 2020January 6, 2026

Commodore 64 power supplies are notoriously unsafe to use. As a result, all Commodore power supplies have a bad reputation. I won’t say it’s unfair. But it means questions about the Commodore 128 power supply come up frequently on vintage computer discussion groups. Is the Commodore 128 power supply safe to use? The short answer is yes. Here’s why.

Dave Farquhar

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301 keyboard error

Dave Farquhar Retro Computing December 28, 2020December 18, 2020

Ah, the 301 keyboard error. The POST error you might be able to fix with your bare hands, or could require a soldering iron. Hopefully that doesn’t scare you off. It’s more frequently a pretty easy fix, especially if the PC isn’t terribly old.

Dave Farquhar

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HP Touchpad tablet

Dave Farquhar Retro Computing December 22, 2020March 2, 2022

The HP Touchpad tablet was, dare I say it, the biggest technological flop of the 2010s. It was HP’s attempt to compete head to head with Apple with a premium-priced tablet that didn’t run Android and, of course, didn’t run Apple’s iOS. Instead it ran WebOS, an operating system it acquired from Palm, Inc.

HP didn’t meet expectations with the Touchpad, and discontinued it after just 50 days on the market. But there are lessons to learn from HP’s experience with its tablet, even if it’s largely forgotten today. Read more

Dave Farquhar

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Commodore SFD-1001

Dave Farquhar Retro Computing December 20, 2020December 7, 2023

The Commodore SFD-1001 is a somewhat obscure Commodore disk drive that found itself in an odd spot. It was a nearly state of the art drive when Commodore released it circa 1983, but it worked with a computer line that Commodore was phasing out. It gained a cult following regardless, and retains a fair bit of mystique, and collector interest, to this day.

Dave Farquhar

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