Brand: Sinclair Research Ltd. / Investrónica SA
Model: ZX Spectrum 128
Country of origin: Spain
Manufacturer: Sagitron (Madrid)
Launch date: September 1985
Price: 44.250 Pts
Board design: Martin Brennan, John Mathieson, Ben Cheese
Software: Martin Brennan, Kevin Males
Case design: Rick Dickinson, Guillermo Capdevila (heat sink, keypad)
Dimensions: 343 × 152 × 41 mm
(feet adds 2 mm; keys adds 6 mm)
Height with legs extended: 65 mm
Weight: 1208 g (keypad: 182 g)
Box dimensions: 375 × 292 × 138 mm
In the early 80’s, the Spanish government had mandated that all computers had to support the Spanish alphabet and show error messages in Spanish. Sinclair’s distributor Investrónica began development to overcome these restrictions and also added some new features, such as a RS232/Midi port, 3-channel sound chip and RGB-monitor output.
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In July of 1985, Spanish company Eurohard who had bought Dragon Computers a year earlier, managed to convince the Spanish government to pass a law taxing all imports of foreign computers—the “Impuesto sobre Computadoras y Periféricos” (ICP) or “Tax on Computers and Peripherals”. But under pressure of other computer manufacturers, a month later that law was changed to only apply the import tax to computers with 64 kB of memory or less.
Thus Sinclair’s Spanish distributor Investrónica started to develop a Spectrum with more than 64 kB of RAM: the ZX Spectrum 128 (code-name “Derby”). All development was done in Cambridge.
The board was designed by Martin Brennan, John Mathieson and Ben Cheese. It was manufactured by Sagitron in Madrid.
The “Editor ROM” or “ROM 0” was developed by Brennan (Basic editor and RS232 routines, taken from Interface 1), Kevin Males (General Instruments AY-3-8912 sound chip and MIDI interface) and an unknown Spanish person. Their initials can be found at the beginning of the ROM: “MB KM AT”.
The Rick Dickinson designed case received an additional head sink designed by Chilean Guillermo Capdevila. Celluloid Dalsland AB of Sweden produced these. Membranes were made by Nameplates for Industry (NFI) of the Isle of Wight.
The keypad was also designed by Capdevila. At one point it was considered adding a ball to enable it to be used as a mouse.
The ROM is actually an EPROM and is handwritten labeled “Derby”. There is a full screen variable editor: EDIT variable$. Other new keywords are RENUM, DELETE, WIDTH, PLAY and SPECTRUM. The WIDTH command set the number of columns for RS232. However, the code is broken and was therefore not mentioned in the manual.
The cursor doesn’t change shape between Lower case, Caps lock, Graphics mode or Extended mode as does the original Spectrum and its precursors, but its mode is indicated by a status bar. When entering an invalid program line, the cursor changes into an actual bug-shape. Program lines are wrapped at the colon character. Keywords can only be entered in Caps mode (MAYUSCULAS), to differentiate it from variables which could have the same name as reserved keywords.
The CLK connection on the edge connector is not actually connected to the CPU’s clock signal—this must be manually added if peripherals (such as the DivMMC) that use this signal are to be used.
The composite signal on the DIN socket is monochrome, RF sound carrier is 5.5 MHz (PAL B/G) which is incompatible with the UK (6 MHz, PAL I). The CPU clock speed = 3.54690 MHz.
In January of 1986 Spain joined the European Union and the ICP tax would become a moot point. The ICP tax was eventually repealed in 1991.