Sinclair Research
@sinclairresearch
Customer support for your ZX80, ZX81 and other classic hardware. We’re sorry to tell you that your warranty has expired.
“Are you so old that your first Windows was 95 or 3.1 or …” Let me stop you there.
Sinclair Research Internal Memo, 1982: RE: Customer complaint about colour bleed Proposal: Rename it. Suggested alternatives: - Chromatic Overflow - Palette Enthusiasm - Colour Sharing (Mandatory) Approved: "Attribute clash." Keep it vague.
The ZX81 had no moving parts. No fan. No disk drive. No mechanical keyboard. It was, in engineering terms, a warm slab of silence. It was also, in user terms, a warm slab of silence, because it had no sound output. Silence was the whole product.
The Spectrum came with a coiled cable that connected it to the TV via an RF modulator. Over time, the coil developed a specific curl that would not flatten out. Forty years later, the cable is still coiled. The Spectrum is in a drawer. The cable has outlasted the hobby, the marriage, and the TV.
Who remembers discovering that PEEK and POKE could read and write directly to memory? One moment you were printing "HELLO" in a loop. The next you were staring at raw hexadecimal and questioning the nature of reality. There was no middle ground.
The ZX81 had a FAST mode and a SLOW mode. FAST mode turned off the display to run programs quicker. SLOW mode kept the display on but ran like treacle. You could have speed or information, but not both. Modern software has the same problem but pretends it does not.
Sinclair Research Inter-Office Memo, 1983: Re: The ZX Microdrive wafer cartridges. Engineering reports that the tape loop inside each cartridge travels at approximately 30 inches per second. It is also approximately 200 inches long. We have done the maths. Please do not ask us about reliability.
The Spectrum had 6,912 bytes of screen memory. Every byte was mapped to a fixed location on the display. If you wrote data to the wrong address, you did not get an error. You got art. Unintentional, unreproducible, occasionally alarming art.
Fun fact: The ZX81 television output was so unstable that pressing a key could make the picture roll. You had to type without looking at the screen, then release the key and hope. It was touch typing, except the touching made everything worse.
Who else learned what "syntax error" meant before they learned what "syntax" meant? The Spectrum taught you failure first and vocabulary second. This remains the most efficient educational method ever devised.
The Spectrum +3 had a built-in 3-inch floppy drive. Not 3.5-inch, like everyone else. Three inches. Sinclair looked at an emerging industry standard and said "but what if it was slightly smaller and completely incompatible" and Amstrad, to their credit, agreed.
The ZX Spectrum manual had a chapter on binary arithmetic. It explained AND, OR, and NOT to children who had not yet learned long division. Some of those children went on to design processors. The rest went into estate agency. Both groups blame the Spectrum.
There were people who typed in 3,000-line BASIC programs from magazines without understanding a single line of code. They did not know what a variable was. They did not know what a loop was. But they knew that line 2,450 had a comma where it should have been a semicolon. Respect.
Fun fact: The ZX81 Z80 processor ran at 3.25 MHz, but spent most of its time generating the television display instead of running your program. The CPU was less of a computer and more of a very expensive TV signal generator that occasionally did some maths on the side.
Sinclair Research Product Clarification: The ZX Spectrum is not waterproof. We mention this because a customer has written to ask. We are unsure what prompted the question. We do not wish to know. Please keep the Spectrum away from all liquids, including but not limited to tea.
In 1982, the fastest way to share a program with a friend was to hand them a cassette tape. If they lived far away, you posted it. Second class. It arrived in three days. The program took four minutes to load. Total transfer time - three days and four minutes. We called this networking.
The ZX81 motherboard had exactly four chips in the original design. Four. The Z80 CPU, a ROM, a RAM, and the custom logic chip. Modern motherboards have components numbering in the thousands. The ZX81 looked at computing and said "how hard can this be" and the answer was "not very, apparently."
Who else had a Spectrum program they were genuinely proud of but never showed anyone because explaining what it did was more effort than writing it? "It sorts numbers." "What numbers?" "Any numbers." "Why?" And there it was. The first existential crisis of your programming career.
Sinclair Research Internal Memo, 1983: Re: Customer request for a backlit screen. The ZX Spectrum does not have a screen. It borrows your television. If the customer requires backlighting, they should position a lamp behind their television set. We trust this resolves the matter.
The ZX Spectrum cassette port operated at 1500 baud. That is roughly 187 bytes per second. A modern fibre connection is about 53 million times faster. And yet the modern connection still feels slow when you are waiting for a web page to load. Patience has not scaled with technology.
Sinclair sold computers by mail order. You posted a cheque to Cambridge and waited six to eight weeks. Sometimes twelve. Occasionally never. It was like crowdfunding, except the product already existed. In theory.