Sinclair developed the ZX Spectrum 128 (code-named Derby) in conjunction with their Spanish distributor Investrónica. Investrónica had helped adapt the ZX Spectrum+ to the Spanish market after the Spanish government introduced a special tax on all computers with 64 KB RAM or less which did not support the Spanish alphabet (including ñ) and show messages in Spanish.

New features included 128 KB RAM, three-channel audio via the AY-3-8912 chip, MIDI compatibility, an RS-232 serial port, an RGB monitor port, 32 KB of ROM including an improved BASIC editor and an external keypad. (only officially released in Spain.

The machine was simultaneously presented for the first time and launched in September 1985 at the SIMO '85 trade show in Spain, with a price of 44,250 pesetas. Because of the large amount of unsold Spectrum+ models, Sinclair decided not to start selling in the UK until January 1986 at a price of £179.95. No external keypad was available for the UK release, although the ROM routines to utilise it and the port itself, which was hastily renamed "AUX", remained.

The machine resembles a Sinclair Spectrum +, but has red lettering and a large heat sink on the right hand side, this was needed as the new chips and architecture produced more heat than the case could dissipate.

This was the first Spectrum that could be connected to scart or RGB monitor, the rear of the machine had this, and the PSU socket and the standard Expansion I/O, as well as the RF socket.

On the front is the Keypad socket and the leftt hand side has the RS 232, and the mic and ear ones for tape loading/saving.

Sadly the machine was only on sale for a few months before Amstrad bought the rights to the Sinclair name and IP, and the machine was altered slightly and became the Spectrum +2

Around 30,000 of these machines made it into market, and are becoming less common today.

CPU Zilog Z80 A
SPEED 3.5469MHz
RAM 128kb
ROM 32kb (16k 48k Basic + 16k 128k Basic)
TEXT MODES  32 x 24
GRAPHIC MODES  256 x 192
COLORS  8 with two tones each (normal and bright)
SOUND 3 channels, 7 octaves (Yamaha AY-3-8912)
SIZE / WEIGHT  320 x 150 x 45 mm

Photograph © Bill Bertram 2006

Our model was kindly donated by Paula from Norfolk

Manufacturer: Sinclair
Date: January 1986

This exhibit has a reference ID of CH2584. Please quote this reference ID in any communication with the Centre for Computing History.