Up for sale is a rare, original Sinclair ZX81 Unassembled Kit from 1981 - a true gem for vintage computing enthusiasts, collectors, or anyone interested in retro tech history! This is the kit version of the iconic ZX81 personal computer, designed by Sir Clive Sinclair and famous for bringing affordable home computing to the masses. Sold as a mail-order kit back in the day for hobbyists to build themselves, these unassembled sets are increasingly hard to find in complete, open-box condition like this one.The ZX81 was a groundbreaking machine: powered by a Z80A processor, it featured 1KB of RAM (expandable), monochrome graphics output to a TV, and used cassette tapes for storage. It ran Sinclair BASIC and helped kickstart the home computer revolution in the UK and US. Over 1.5 million ZX81s were sold worldwide, but the unassembled kits were less common and often returned due to assembly challenges - making survivors like this highly collectible. Recent sold listings for similar ZX81 kits in good condition have fetched $395 to over $1,000, depending on completeness and region.This kit is complete with all hardware components and includes everything shown in the photos (taken from all angles for transparency). It comes in its original black cardboard box with colorful graphics and setup diagrams, plus the protective styrofoam inserts. The box shows some creases and minor edge wear due to age, including light scuffs on corners and sides from storage over the decades, but overall it's in very good condition—solid structure, no major tears or damage, and it displays beautifully.
What's Included:

• Main printed circuit board (PCB) - Green, unmarked, ready for assembly.
• Membrane keyboard overlay with 40 multi-function keys (QWERTY layout, pressure-sensitive).
• Plastic clamshell case (top and bottom halves, black wedge-shaped design).
• Bag of integrated circuits (ICs) and sockets: Includes the Z80A 8-bit CPU, Ferranti ULA chip, 8KB ROM with Sinclair BASIC, and 1KB RAM chips (likely two 2114 or equivalent).
• Bags of passive components: Resistors, capacitors, diodes, and other small parts for soldering.
• RF modulator for TV output (UHF connection).
• Power adapter (9V DC, original Sinclair-style with US plug; tested and outputs correct voltage).
• Connection cables: TV lead, cassette recorder leads (EAR/MIC 3.5mm jacks), and plugs.

Please note: The assembly instructions and computing manual are not included in this kit (though the box references them with setup diagrams for TV, cassette, and power). Digital versions of the manual are widely available online for free if needed for assembly. No TV, cassette recorder, or additional expansions are included - just like the original kit. Everything is bagged and organized as it would have been from the factory. I haven't attempted assembly, so it's sold as-is for collectors or builders. If you're handy with a soldering iron, you could bring this 1980s icon to life!This would make an amazing display piece for a retro computing collection, a fun project for electronics hobbyists, or a nostalgic gift. Don't miss out on this piece of computing history - these kits don't come up often in this condition!
Item Specifics:

• Brand: Sinclair Research
• Model: ZX81
• Type: Home Computer (Unassembled Kit)
• Vintage: Yes (1981)
• Country/Region of Manufacture: United Kingdom (assembled in Scotland by Timex)