This Cassette Tape Emulates the ZX Spectrum

The ZX Spectrum was released in 1982 and would go on to become one of the best-selling computer models in history, despite the fact that it was never sold in the United States. Its success was due to the fact that it was extremely affordable at just £125 (later £99), but still quite powerful. It had a Zilog Z80A processor running at 3.5MHz and at least 16KB of RAM, with most getting the 48KB upgrade. Like other computers from the era, the ZX Spectrum didn’t have any built-in storage and cassette tapes were commonly used for storing software and data. Redditor JamHamster put a new spin on that idea by cramming a Raspberry Pi Zero W into a cassette tape and using it to emulate a ZX Spectrum.

The ZX Spectrum was already a very small computer—much smaller than popular competitors like the Commodore 64 and Apple IIc. But that pales in comparison to the Raspberry Pi Zero W, which is about the size of two sticks of gum sitting side by side. The Raspberry Pi Zero W’s small footprint makes it ideal for projects that need to be compact, but this project pushes that to the limit. The entire computer, including ports and jacks, fits entirely inside of a standard cassette tape. The cassette tape isn’t functional, of course, but JamHamster previously built an Arduino cassette tape that could be used to load software onto a ZX Spectrum.

This project doesn’t contain any original ZX Spectrum hardware, but it is perfectly capable of emulating the ZX Spectrum in order to play games. But software isn’t the highlight of this project. JamHamster’s work here is impressive because of how much he was able to fit in the cramped space inside of the cassette tape. This required significant trimming of the Raspberry Pi Zero W, including cutting off portions of the PCB entirely. Video is output through the Pi’s built-in composite video pads and audio is output through PWM via the GPIO pins. Power is input through the standard micro USB port and JamHamster even found room to add two USB-A ports so that controllers can be connected. The backside of the cassette has a massive aluminum heatsink to the keep the Pi nice and cool, even under heavy load. The result looks fantastic and is completely functional.