The Cheetah SpecDrum, released in 1985 by Cheetah Marketing Ltd, transformed the Sinclair ZX Spectrum from a simple home computer into a sophisticated 8-bit digital drum machine. Developed by musicians Alan Pateman and Peter Hennig, the device stood out for its affordability, retailing at just £29.95 during an era when standalone professional drum machines typically cost several hundred pounds. This price point made high-quality digital percussion accessible to a wide audience, leading to the sale of approximately 30,000 units in its first year alone.
The hardware itself was a compact module that plugged directly into the Spectrum's rear expansion port. Internally, it utilized a relatively straightforward design centered around a Ferranti Digital-to-Analog Converter (DAC) chip, a quad op-amp, and a quad NOR gate. Because it bypassed the computer's internal "beeper," it required an external amplifier or hi-fi system, connected via a standard phono (RCA) lead, to produce its punchy, 8-bit sampled sounds.
On the software side, the SpecDrum provided a comprehensive environment for music creation. The bundled software featured a pattern editor where users could program rhythms in real-time or step-time, storing over 1,000 individual rhythms. These patterns could be arranged into full songs, with memory capacity for 16 songs, each containing up to 64 different rhythm patterns. The standard "kit" provided eight essential drum sounds—including bass, snare, tomtoms, cowbell, and handclaps—that were often compared to the iconic LinnDrum. To expand the sonic palette, Cheetah released additional themed kits on cassette tape, such as Afro, Latin, and Electro.
While it lacked native MIDI support, the SpecDrum remains a celebrated piece of retro-computing history. Its legacy continues through modern enthusiasts who have developed methods to load custom samples and through software emulations like the SpecDrum 2000 plugin, which allows modern producers to integrate its classic lo-fi grit into contemporary digital audio workstations.
