- The original ZX Spectrum is remembered for its rubber keyboard.
- It was originally released on 23 April 1982 with 16KB Model and 48KB Model.
ZX Spectrum 16K / 48K (1982)
- This 48K Spectrum introduced a new casing with an injection moulded keyboard and a reset button that was basically a switch that shorted across the CPU reset capacitor.
- The machine outsold the rubber-key model 2:1 in early stage. However, some retailers reported a failure rate of up to 30%, compared with a more usual 5%-6% for the older model.
ZX Spectrum+ (1984)
- The appearance of the ZX Spectrum 128 was similar to the ZX Spectrum+, with the exception of a large external heatsink added to the right hand end of the case.
- New features included 128K RAM, 3 Channel audio, an RGB Monitor port, 32KB of ROM including improved BASIC editor.
ZX Spectrum 128K (1985)
- The ZX Spectrum +2 was Amstrad's first Spectrum, after their purchase of the Spectrum range and "Sinclair" brand in 1986.
- The machine featured an all-new grey case with a spring-loaded keyboard, dual joystick ports, and a built-in cassette recorder.
ZX Spectrum +2 (1986)
- The ZX Spectrum +3 looked similar to the +2 but featured a built-in 3-inch floppy disk drive.
- Some older 48K and 128K games were incompatible with the machine. There was a regression in sound quality from the previous 128K models.
ZX Spectrum +3 (1987)