Some background on the target platform. The original ZX Spectrum was launced in 1982. In some regards it can be considered the British equivalent of the Apple ][ as it used a variety of hardware tricks to keep costs down. In 1985 Sinclair launched the Spectrum 128 in Spain. In 1986, before they had even bought the company, Amstrad had tooled up to produce a clone of the 128, the Spectrum +2. In 1987 Amstrad launched the Spectrum/PCW hybrid, the Spectrum +3 with a disk drive. After the existing stock of gray-cased +2s were sold, Amstrad briefly sold the black-cased +2A with depopulated +3 motherboards. It soon replaced these motherboards with a cut down design that removed the disk functionality entirely. This was the +2B, although it still said +2A on the case. It was manufactured between 1988 and 1990 and continued to be sold until at least 1992, making it the most common variant of the Spectrum 128.
- CPU: Zilog Z80A @ 3.5469MHz.
- RAM: 128K in eight banks of 16K (pageable in the top 16K of the address space).
- Video: ULA provides 256 x 192 pixels, 15 colours, two colours per 8×8 pixel cell. The ZXodus][Engine rapidly updates the attributes to provide a view window of 144×144 pixels with 8×1 sized cells.
- Audio: AY-3-8912 three channel, eight octave programmable sound generator and 1-bit CPU-driven audio.