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.
