It’s Elite, For The Commodore Pet

November 11, 2026 by Jenny List 5 Comments

A few times in the life of someone interested in technology, there comes along something which after seeing it, you know the field is never going to be the same again. For a teenage future Hackaday writer this came in seeing Elite, on a BBC Micro. Nowadays an open world game is normal, but in the mid-1980s it was mind-blowing. Of course, such a powerful piece of software couldn’t be ported to any old computer, so owners of less capable machines were left envious of their more well-heeled friends.

It will be a surprise to Commodore Pet owners then, that over four decades later, [David Given] has ported the game to their platform. It’s not such a leap, as the Pet has the same (albeit slower) 6502 as the BBC Micro, and the game requires the Commodore machine to have 32k of memory.

So what you get is Elite, but with the Pet’s block graphics rather than the higher-resolution you’d have seen on the newer machines. He admits it doesn’t play well and that the code is something of a mess, but we suspect 32k Pet owners in 2026 won’t be too bothered by this. All the code and disk images are there in the repository, and you can see it at work in the video below the break. Meanwhile if you’re curious about the Elite codebase, you can take a look at it yourself.

Continue reading “It’s Elite, For The Commodore Pet” →

Is It A Pet? No, It’s A Teacher’s Pet!

May 1, 2026 by Jenny List No comments

Here at Hackaday we cover the world of retrocomputing, which means that we see all manner of older computers in our everyday work. We might even claim that we’ve seen them all, were it not that every now and then something comes along which surprises us. [Tynemouth Software] has done just that, with an unexpected Commodore. It’s a Commodore 4064, something that was new to us, but which is best described as a Commodore 64 in a PET case. He’s bringing this one back to life.

For those with weak early-Commodore-fu, maybe it’s worth a quick recap. The PET was Commodore’s big hit from the late 1970s, and it took the form of an all-in-one machine with a CRT display built in. They packed a 6502, BASIC, blocky monochrome graphics, and unexpectedly an IEE-488, or GPIB port. Meanwhile the 64 was the company’s smash hit early 1980s home computer in a compact console design, with high-res color graphics for the time on your TV, and a synthesizer chip that’s still legendary in 2026. Combining a 64 mainboard with the super-robust PET case appears to have been part of Commodore’s business and education offerings.

This one appears to have been in the damp, because that board is definitely more than a bit grubby. After a lot of debugging its power and video circuits, including an unexpected sync splitter board to drive the non-composite monitor, he narrows down the problem to a dodgy ROM and some memory errors.

It seems there’s some question in Commodore enthusiast circles as to whether these machines were assembled from surplus PET parts, but he puts that one to bed by pointing out the custom metalwork and the few custom Commodore 64 features on the board. All in all it’s an interesting dive into an unusual 8-bit machine.

We’ve seen [Tynemouth] a few times here, perhaps most notably with their modern take on a ZX80.

Restoring A Commodore PET 3032 In Rough Condition

March 8, 2026 by Maya Posch 11 Comments

The restored PET/CBM 3032. (Credit: Drygol, retrohax.net)

The Commodore CBM 3032 is a successor to the original Commodore PET 2001, yet due a conflicting trademark issue with Philips these first European PETs were called ‘CBM’ instead. Hence the labeling on the CBM 3032 that [Drygol] had in for a restoration, which would have been produced somewhere between 1979 and the cessation of its manufacturing a few years later. This former machine of the University of Szcezecin in Poland had languished in a basement until a local demoscene group came across it and wanted to use it, after a restoration.

Although at first glance from just the front it didn’t look too shabby, problems were apparent from just a walkaround, including rusty and buckled paneling, showing that the time spent in storage had not done it any favors. Internally there was decades worth of dust, along with a dodgy potentiometer, cold joints and some PCB-level bodges that may or may not have been there from the factory.

The main case was disassembled by drilling out the rivets to gain full access to every nook and cranny, allowing for a good cleaning and repainting prior to putting in fresh rivets. On the PCB side of things, a potentiometer and an LM340KC-12 linear regulator in a TO-3 package had to be replaced, after which the system managed to boot reliably once in every three attempts.

Fixing this took basically cleaning all contacts and IC sockets, as well as refurbishing the keyboard, with corrosion and the occasional broken trace causing a lot of grief. Ultimately the system was restored and ready to be put into demoscene service.

Ken Shirriff working on the Commodore PET

This 8-Bit Commodore PET Was Hard To Fix

January 6, 2026 by John Elliot V 13 Comments

Over on [Ken Shirriff]’s blog is a tricky Commodore PET repair: tracking down 6 1/2 bad chips. WARNING: contains 8-bit assembly code.

The Trinity of 1977 which started the personal computer revolution were the Apple II, the Commodore PET, and the TRS-80. In this project it’s a failing Commodore PET which is being restored.

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A view of the schematics for each major component.

Simulating The Commodore PET

August 26, 2025 by John Elliot V 2 Comments

Over on his blog our hacker [cpt_tom] shows us how to simulate the hardware for a Commodore PET. Two of them in fact, one with static RAM and the other with dynamic RAM.

This project is serious business. The simulation environment used is Digital. Digital is a digital logic designer and circuit simulator designed for educational purposes. It’s a Java program that runs under the JVM. It deals in .dig files which are XML files that represent the details of the simulated hardware components. You don’t need to write the XML files by hand, there is a GUI for that. Continue reading “Simulating The Commodore PET” →

A Tricky Commodore PET Repair And A Lesson About Assumptions

April 14, 2025 by Maya Posch 11 Comments

The PET opened, showing the motherboard. (Credit: Ken Shirriff)

An unavoidable part of old home computer systems and kin like the Commodore PET is that due to the age of their components they will develop issues that go far beyond what was covered in the official repair manual, not to mention require unconventional repairs. A case in point is the 2001 series Commodore PET that [Ken Shirriff] recently repaired.

The initial diagnosis was quite straightforward: it did turn on, but only displayed random symbols on the CRT, so obviously the ICs weren’t entirely happy, but at least the power supply and the basic display routines seemed to be more or less functional. Surely this meant that only a few bad ICs and maybe a few capacitors had to be replaced, and everything would be fully functional again.

Initially two bad MOS MPS6540 ROM chips had to be replaced with 2716 EPROMs using an adapter, but this did not fix the original symptom. After a logic analyzer session three bad RAM ICs were identified, which mostly fixed the display issue, aside from a quaint 2×2 checkerboard pattern and completely bizarre behavior upon running BASIC programs.

Using the logic analyzer capture the 6502 MPU was identified as writing to the wrong addresses. Ironically, this turned out to be due to a wrong byte in one of the replacement 2716 EPROMs as the used programmer wasn’t quite capable of hitting the right programming voltage. Using a better programmer fixed this, but on the next boot another RAM IC turned out to have failed, upping the total of failed silicon to four RAM & two ROM ICs, as pictured above, and teaching the important lesson to test replacement ROMs before you stick them into a system.

This Rohde & Schwarz Computer Is A Commodore PET

June 14, 2023 by Jenny List 24 Comments

The IEE-488 or GPIB bus for controlling instruments by computer has existed now for many decades. It’s often implemented over USB or Ethernet here in 2023, but the familiar connector can still be found on the backs of pricey instruments. In the earlier days of GPIB when a powerhouse Linux laptop was decades away, what computer did the would-be GPIB user reach for? If they were a Rohde and Schwarz customer in the late 1970s the chances are it would have been the R&S PUC process controller, an 8-bit microcomputer that under its smart exterior turns out to be an enhanced Commodore PET. [NatureAndTech] has one for teardown, and you can see it in the video below the break.

Readers with long memories will remember that the PET had an IE-488 bus on a card edge connector, and it’s possible that’s why R&S took it as the basis for their machine. But this isn’t merely a PET in a fancy box, instead it’s a fully new PET-compatible computer, and it has some interesting features. There’s more memory than the original, a set of disk drives, and an expansion bus complete with a high-res graphics card allowing pixel graphics rather than text. Surprisingly though it has a BASIC interpreter it’s a hardware clone of the PET only, the ROM is unique to Rohde & Schwarz.

We think this machine is probably rare enough that we’re unlikely to see one in the flesh, but it’s been a fascinating thing to examine. You can join in with the video below the break, or you can look at the PET’s impact on a more recent scene.

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