Sinclair ZX Spectrum Plus

The ZX Spectrum+, also known as "Sinclair Spectrum plus" was a Z80 microprocessor based home computer manufactured by the Sinclair Research Company in approximately 1984. Inside, it had an "Issue 3" spectrum motherboard with 48 KB memory. The internal board and electronics was identical to the previous versions, hence this was mainly a cosmetic upgrade.

This computer had a design problem in that the ribbon cable went over the voltage regulator heatsink, and eventually the cable failed. It was a typical problem, which plagued the machines; otherwise, the QWERTY keyboard was high quality with well-crafted key tops.

I have an article showing how you can modify the unit to prevent the ribbon cable from being damaged.

This was the first Sinclair home computer to have a full sized keyboard with full-stroke keys, and was a huge improvement over the "dead flesh" keys. The intention was to compete with the Commodore market in America, which had grown in popularity because of its full-sized keyboard.

Keyboard

One hardware improvement was a small reset switch on the left-hand side of the case, which helped, as previously spectrum owners had only one option to pull the plug to reset the machine.

Key tops

The Spectrum+ key tops have curved surfaces and steps. This was somebody's idea of ergonomics back in a time when it would have been an emerging science. This was one of those designs that you either loved or hated depending upon your typing skill. Fortunately, many people who used this could only type with two thumbs and played games on it so it was not much of an issue.

I use all of my fingers for typing and I could never get used to this keyboard. When you press the keys, there is an absence of sensation, because it uses a membrane layer for the switch contacts.

Sinclair Logo

In 1983, Clive Sinclair received a Knighthood for services to British Industry. He was an amazing man ahead of his time and a pure genius. I remember seeing some of his earlier Radionics kits in electronics magazines and being impressed by them. He was the last of the true British entrepreneurs.

Cost / eBay

This was a mass-produced item and there are many units around, however due to the ribbon cable failure there are not many working ones. If you can get a broken one, it may be possible to repair the flex circuit with conducting ink. Alternatively, its motherboard is identical to the previous models and it would make useful spares.

It still has components of value such as the RF modulator, memory integrated circuits, ULA, and an original Z80 processor. At one time, these retailed for approximately 180 pounds, and it is a nice piece of history worth having.

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