Sinclair ZX Spectrum+

The Sinclair ZX Spectrum+ placed the proven 48KB Spectrum electronics in a larger QL-inspired case with a 58-key keyboard and reset button. The new layout provided dedicated editing and mode keys while retaining compatibility with the established Spectrum software library.

Existing 16K and 48K machines could be converted using an official case-and-keyboard kit. The Plus improved presentation and typing but remained internally close to the original design and inherited its single-channel sound and cassette storage.

Notable Features

• QL-inspired enclosure provided 58 moving plastic keys over a membrane mechanism.
• Dedicated reset button and editing keys improved day-to-day use.
• Official upgrade kits allowed earlier Spectrum boards to be fitted into the new case.

Historical Significance

• Extended the commercial life of the original 48KB architecture.
• Established the keyboard styling carried into the first 128KB Spectrum.

Collector’s Notes

• Some surviving examples are factory-built units while others are official or third-party conversions.
• Membrane layers remain consumable parts despite the improved key mechanism.

Specifications

Technical Information
Name	Sinclair ZX Spectrum+
Manufacturer	Sinclair Research Ltd
Launched	Monday, October 1, 1984
Discontinued	1/1/1986
Country	United Kingdom
CPU	Zilog Z80A at 3.5 MHz
Units Sold
Operating System	Sinclair BASIC
CPU Speed	3.5 MHz
RAM	48KB
ROM	16KB containing Sinclair BASIC
Display	32 x 24 characters
Graphics	256 x 192 pixels; 15 colours with 8 x 8 attribute cells
Sound	Single-channel beeper
Storage	External cassette; optional ZX Microdrive
Keyboard	Integrated 58-key moving-key membrane keyboard
I/O	RF television, cassette EAR/MIC and rear expansion bus