Retro Computing Archives

The killer POKE for the Commodore PET

Dave Farquhar Retro Computing February 9, 2021June 5, 2026

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

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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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 the PET, 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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CRT burn in

Dave Farquhar Retro Computing December 16, 2020December 7, 2020

CRT burn in is a phenomenon where an image becomes permanently etched into a monitor’s phosphors. This causes the outline of the image to remain visible, even when the monitor is off. It’s a problem that we frequently find on vintage CRT monitors today.

Burn in is most frequently associated with CRTs, though it can happen with other display types. Modern technology usually mitigates burn in on newer displays, so burn in rarely happens with modern displays, such as LCD or LED displays.

Dave Farquhar

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Commodore 1084 monitor

Dave Farquhar Retro Computing December 10, 2020January 6, 2026

The Commodore 1084 monitor was Commodore’s flagship monitor, a monitor that worked with everything they produced in the late 1980s, including the C-64, the C-128 in 40 and 80 column modes, the Amiga line, and Commodore’s CGA-equipped PC clones like the Commodore Colt. Its versatility makes it popular with retro computer enthusiasts today. Not only does it work with almost any Commodore computer, it also works with a lot of non-Commodore computers.

Dave Farquhar

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Baking computer chips: Fixing chips in an oven

Dave Farquhar Hardware, Retro Computing December 7, 2020May 21, 2024

Does baking computer chips fix them when they’re broken? Can you fix computer chips in an oven? The answer is sometimes. Unfortunately, it’s difficult to know when it will help, and when it does, we may not know why. But, when faced with a broken chip, we don’t exactly have anything to lose, either.

Baking computer chips does seem to fix them, at least sometimes. Whether it works depends entirely on why the chip failed in the first place, which isn’t always possible to know.

Dave Farquhar

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Jonard EX-2 review: The best chip puller

Dave Farquhar Hardware, Retro Computing November 17, 2020October 31, 2020

If you’re looking for the best chip puller or IC extraction tool, I don’t think anyone will argue with my assertion it’s the Jonard EX-2. I finally picked one up this fall after watching various retro Youtubers use them for more than a year. The videos aren’t exaggerating. This chip puller makes life with retro machines much easier. This is my Jonard EX-2 review.

Dave Farquhar

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