ZX Spectrum/Trivia

Trivia about the ZX Spectrum includes:

Uncle Clive

• Clive Sinclair was an electronics enthusiast, but wasn't all that bothered about making computers. The ZX line came about because he saw a gap in the market, and wanted to raise money to fund research into his real passion, sustainable transport.
• He reportedly didn't like the Spectrum at all, mainly because it became known as a games machine, which was something he didn't want to make. He wanted his company to push technological innovation, and its computers to be used for education and research.
  • A lot of coders and hardware hackers started on the Speccy, so he was arguably successful there.
  • The fact that it had a much higher failure rate than the ZX81 probably didn't help there.
  • He tried again with the QL - which, by most accounts, was a pretty good machine when they finally got it finished, but it suffered some serious launch delays and some odd quirks in the early versions.

Hardware

• A lot of original 48K Spectrums actually contained 80K of RAM, of which 32K was defective and unused. The Spectrum's RAM was treated as 2 banks - the lower 16K common to all early Spectra, and the upper 32K in the fancy-pants 48K machines. In the very early 80s, memory manufacturers were switching to 64K banks, but at first the new chips had a high failure rate. Sinclair saved money by buying chips that were known to have faults in only one half of the RAM, and using these to make up the 32K bank - with only the good half of each chip being used.
  • Coders soon noticed that routines ran faster in the higher bank, because the lower bank was contended - the graphics chip grabbed screen data from the same bank, and the CPU had to wait its turn.
  • 128K machines mostly used two 64K banks, one of which was contended. Some clones used different configurations with more or less, or occasionally no, contention.
• Being shipped without a gamepad meant that all games had to support keyboard controls, and the arrow keys weren't in the best positions for game playing. Instead Q, A, O and P soon became the unofficial defaults for up, down, left and right. These keys would eventually wear out, cre*ting *uite * dem*nd f*r re*l*cement keyb**rd membr*nes.
• The CPU runs at 3.5MHz, which sounded fast compared to its more expensive rival, the Commodore 64, whose processor putters along at 1 MHz. However, Clock Speed isn't a good way to compare processors. For a start, the Z80 needs 2-3 times as many "ticks" per instruction, so it really isn't that much quicker; and the C64 has better graphics and sound chips to share the workload. The best we can say is the Speccy's CPU is a bit faster and significantly busier than the 64's.
• Spectrum manufacturing had a high failure rate, which reduced its profitability, at least in the early days. The failures came partly from Timex not having much experience in computer manufacturing, but mostly from Sinclair's brutal cost minimisation - which led to choosing cheap components, and often running them beyond their design spec.

Add-ons

• Sinclair tried to get the ROM cartridge ball rolling by releasing a total of ten games on cartridge in 1983 (the year the Interface 2 came out) - there's a list of them here. All the games were already popular on tape, but were discontinued on cartridge within months - almost as if people who bought the cheapest colour computer on the market weren't willing to pay a premium to make the games load faster. Who'd'a' thunk it?
  • Another reason ROM cartridges weren't popular is that they only hold 16K, which restricted their possible game catalogue despite advertising saying "you can run them all on 16K RAM Spectrums, even if they were originally written for 48K machines." Hacks have since been developed to overcome the limit.
    • The cartridge replaces the internal ROM, so coders do at least get to use the whole 16K. Normal 16K games get quite a bit less because the first 6.75K of RAM is dedicated to the screen.
  • Some aftermarket joystick interfaces were sold with spaces for cartridge slots even into the 90s - instead of redesigning the interface, the manufacturers just left the cartridge connector off the circuit board (and the manual).

Names

• The name ZX80 came from the processor, the Z80, with the X representing "the mystery ingredient". ZX81 and ZX82 Spectrum sounded like logical progressions.
  • The Z came from chip manufacturer Zilog ("Z Integrated Logic"), whose founder, Frederico Faggin, said the Z represented "the last word of integrated logic", and the 80 from Intel's 8080, on which the Z80 was based.

Sales

• Amstrad discontinued the Spectrum in 1992. Games and magazines continued to be sold for a short while after. The main UK mags at the time were Crash,^[1] which, err, crashed in 1992, Sinclair User,^[2] and Your Sinclair,^[3] both of which managed to hold out until 1993.
  • Your Sinclair (YS) was brought back in a one-off tribute edition a few years later.
  • The Sam Coupé continued to be sold until 1995, when its third and final manufacturer went under. It sold 12,000 units in those 6 years.