2010, Sinclair Research announced the X-1 two-wheel electric vehicle, which failed to reach production. Products Wrist Calculator The Wrist Calculator was released by Sinclair Instrument in 1977. Multimeter DM2 A digital multimeter with an LED display, measuring voltage (DC and AC), current and resistance, released in 1975. MK14 The MK14 (Microcomputer Kit 14) was a computer kit sold by Science of Cambridge, introduced in 1977 for £39.95. ZX80 The ZX80 home computer was launched in February 1980 at £79.95 in kit form and £99.95 ready-built. In November of the same year Science of Cambridge was renamed Sinclair Computers Ltd. ZX81 The ZX81 (known as the TS 1000 in the United States) was priced at £49.95 in kit form and £69.95 ready-built, by mail order. ZX Spectrum The ZX Spectrum was launched on 23 April 1982, priced at £125 for the 16 KB RAM version and £175 for the 48 KB version. TV80 The TV80 was a pocket television. Launched in September 1983, it used a flattened CRT unlike Sinclair's previous portable televisions. The TV80 was a commercial failure selling only 15,000 units and not covering its development costs of £4m. Sinclair QL The Sinclair QL was announced in January 1984, priced at £399. Marketed as a more sophisticated 32-bit microcomputer for professional users, it used a Motorola 68008 processor. Production was delayed by several months, due to unfinished development of hardware and software at the time of the QL's launch. Hardware reliability problems and software bugs resulted in the QL acquiring a poor reputation from which it never recovered. ZX Spectrum+ The ZX Spectrum+ was a repackaged ZX Spectrum 48K, launched in October 1984. ZX Spectrum 128 The ZX Spectrum 128, with RAM expanded to 128 kB, a sound chip and other enhancements, was launched in Spain in September 1985 and the UK in January 1986, priced at £179.95. Computer peripherals Sinclair created various peripherals for its computers, including memory expansion modules, the ZX Printer, and the ZX Interface 1 and ZX Interface 2 add-ons for the ZX Spectrum. A number of QL peripherals were developed by other companies but marketed under the Sinclair brand. External storage for the Spectrum was usually on cassette tapes, as was common in that era. Rather than an optional floppy disk drive, Sinclair instead opted to offer its own mass storage system, the ZX Microdrive, a tape-loop cartridge system that proved unreliable. This was