I have the main units and power adapter.
type computer
country UK
year 1984
os basic
cpu Z80A
speed 3.54 MHz
ram 128 KB
rom 32 KB
graphic 256×192
colors 8
sound 3 channels, 5 octaves
ports RS-232, expansion, tv, cassette, RGB monitor port
The Sinclair ZX Spectrum 128K — Sound and More Memory
Released in September 1985 in Spain before its UK launch in January 1986, the Sinclair ZX Spectrum 128K was the first major hardware upgrade to the Spectrum line — adding 128 KB of RAM (accessed through bank switching), a three-channel AY-3-8912 sound chip (replacing the original single-channel beeper), a built-in MIDI interface, and an RGB monitor output. Developed in collaboration with Investrónica in Spain, the 128K gave the Spectrum genuine audio capability to rival the Commodore 64’s SID chip, and the additional memory opened up far more ambitious software development.
Why Spain First?
The Spectrum 128K was launched first in Spain — an unusual decision driven by commercial necessity. Sinclair had a strong distribution deal with Investrónica in Spain, and the Spanish government’s requirement that computers sold in Spain have at least 128 KB of RAM made the upgrade essential for continued market access. The Spanish launch allowed Sinclair to test the 128K in a real market before the UK rollout, and the machine was warmly received by Spanish Spectrum users who had been the most vocal advocates for hardware improvements.
AY Sound — A Revelation
The AY-3-8912 sound chip in the 128K transformed Spectrum gaming audio. Where the original Spectrum could only produce beeps of varying pitch and duration, the AY provided three independent sound channels with envelope control, noise generation, and programmable waveforms. The difference in sound quality between a beeper game and an AY game was immediately and dramatically apparent, and software developers quickly exploited the new capability — many 128K games had soundtracks that rivalled those of the Commodore 64 and Amstrad CPC.