Quantcast
Channel: Avaragado's blog » history
Viewing all articles
Browse latest Browse all 6

ZX Spectrum+30

$
0
0

On Friday 23 April 1982, the Royal Navy task force was steaming south towards the Falklands. At the same time, advance forces were preparing in secret to retake South Georgia, a success which would catapult Margaret Thatcher onto the steps of Downing Street all bug-eyed, bouncing off journalists and imploring us hysterically to “Rejoice”.

Meanwhile at a hotel in London the as-yet unknighted gingerboff Clive Sinclair was unveiling the computer that would replace the year-old ZX81 and its wobbly RAM pack. Everybody had been expecting the launch. Speculation about the ZX81’s successor had been appearing in computer magazines for months. Many people expected it to be called the ZX82.

It was, of course, the ZX Spectrum. With high-resolution 256 x 192 pixel, 15-colour graphics, 16K or 48K RAM and a 3.5MHz Z80A processor, it was a substantial step up from its predecessor. A bit more expensive too: £125 for 16K and £175 for 48K.

I found out about the launch the following day, as on that Saturday my Dad took me to London’s glittering Earl’s Court for the Computer Fair. It was the second computer show I’d been to — the first being the previous year’s Personal Computer World show at London’s guttering Novotel in Hammersmith.

Earl’s Court was packed with nerds and protonerds gawping over the likes of the Vic 20 and the TRS-80. The crowds were especially thick around the Acorn stand — at least partially thronged with people who’d ordered and paid for a BBC Micro (launched a few months before) politely enquiring when the hell it would arrive. In those primitive times we were told to “allow 28 days for delivery” of new computers and were lucky if they arrived in less than a hundred.

I remember seeing the Sinclair Research stand. It was immediately obvious there’d been an announcement: one wall of the stand was plastered with a blown-up image of the new machine. Crowds stood several deep, grabbing leaflets and hoping for a glimpse of hardware. When I pushed to the front I could see a portable TV looping through a demo showing off the Spectrum’s capabilities. If memory serves there were no finished units on display: merely a couple of shrines behind glass, untouchable and perhaps with the paint still drying to hide the wood grain.

Naturally it wasn’t possible to hand over your Thatcherite tenners and take a Spectrum home with you — the demo was, I suspect, all breadboards and pixie dust — but staff would be more than happy to take your order, and your cash.

I salivated. A negotiation began with Dad. Neither of us remembers now how much I paid (or promised to pay) and how much was counted as a belated birthday present, but the result was a scribbled receipt — I believe numbered 1151, it’s in the collection somewhere — and the fizzing anticipation of a delivery of a 16K Spectrum in less than 28 days!

I took away with me one of the brochures, the front cover of which was a life-sized picture of the keyboard. Identical brochures fell out of every computer magazine for the next few months. One travelled in my school bag every day, because if you’re going to obsess on something there’s no point doing it by halves.

Twenty-eight days later the Spectrum had not arrived, of course; but the Royal Navy task force had reached its destination, and the news was dominated with the latest from the Falklands War. It wasn’t until sometime in late June, I think, that I scurried home from school to find, finally, a small brown parcel waiting for me. By this time the Argentine forces had surrendered and the war was over.

Sadly there is no unboxing video, as I had left my iPhone in the future. I unpacked everything solemnly, like a reverse Pharaonic burial rite. I plugged in the power (reviewer criticisms included: “still no on/off switch”) and tuned it in to the living room TV. Finally the message “© 1982 Sinclair Research Ltd” stared back at me with a faint shimmer, and I understood what was meant by dot crawl.

Then one by one I loaded the demo games and tools from the supplied Horizons tape, and heard for the first time the soundtrack of the next five years: brrrrrrrrrrbip! brrrrrrrrrrbipplybeebipplybeebipplybeebipplybeeetc!

And I proceeded, as a true geek, to inhale the manual.

I loved that machine. I came to know every part of it. It suffered at my hands. I upgraded it to 48K. I progressed from BASIC to Z80 assembler — like all real programmers, first by hand-assembling to machine code using the table at the back of the manual. I bought a copy of the Complete Spectrum ROM Disassembly — the Spectrum’s OS decoded and annotated, every byte of it, every bug and whistle. I bought an Interface 1 and ZX Microdrive — each cartridge (a squiggly loop of magnetic tape in a small case) able to hold a massive 85K or so, and loading and saving much faster than cassette tape. I learned how to disassemble and hack games, like Manic Miner and Jet Set Willy and Fairlight and Atic Atac and Knight Lore and and and… and I wrote my own. I hacked and coded for money. I was published in Your Spectrum magazine.

My ZX Spectrum

I loved that machine.

I still have it, of course. My ZX Spectrum is an issue one design: light grey keys, with a hand-patched board inside to fix a hardware bug. This makes it one of the first 60,000 manufactured, I believe.

Serial number: 001-000046. That’s pretty early.

I haven’t powered it up for at least twenty years, and I daren’t do so now in case something goes pop. But I’ve taken some photos of it and every piece of software and every book I still have and uploaded them all to Flickr, because if you’re going to obsess on something there’s no point doing it by halves.

In amongst all the tapes, I was very pleased to find my master copy of The School — the text adventure game I wrote (designed with Dave O’Neill, school friend and one of the commenters on my previous blog post). Although I submitted it to several software houses nobody took it on: the game was never professionally released (it wasn’t good enough) and hasn’t been played since the mid-eighties.

But, you know, we’re living in the future now. You can get ZX Spectrum emulators for just about every platform…

All I needed to do to play it was sample the tape, and load it into the emulator. How hard could it be? The standard Spectrum saving routine encoded data on tape at 1500 baud — roughly 1500 bps. Easy to sample. Ten minutes tops, surely: five to play the tape, five to faff.

Now then. Find your nearest ZX greybeard. If that’s me: hello! Ask him (it’ll be a him) what caused the most problems with Spectrum games. He’ll say gloomily: “R Tape loading error” (the R is an error code). You had to play goldilocks with the volume and treble and bass on your cassette player, hunting for the sweet spot that tickled the Spectrum’s distinctive stripy borders. And also, cassette players tended to wind the tape at different speeds, often speeding up and slowing down. With yer Slade and yer Boney M and yer Wham (note: I owned none of these) it made no difference, but with the intolerant and pernickety Spectrum loading code, it sometimes did.

I proceeded to spend hours (spread over several days) sampling the tape, and loading it into the emulator, and watching it fail. Sometimes it would load one of the three chunks of code, sometimes two, but it never reached the third, the longest chunk. R Tape loading error. The bits were corrupt.

I found a different tape player — in fact, one I used for saving and loading software around the time the Marines were yomping over the Falklands. Sampling with this player didn’t work either.

I even splashed out on a new tape player — one with a USB cable, for sampling directly into Audacity on the Mac. Aha! Better! For the first time since 1984, I reached the third chunk of code and saw the loading screen — and here it is:

I was fifteen, OK? There was no such thing as Photoshop. I hadn’t even built my mouse yet.

Anyway, I thought: since it got that far, why didn’t it load the entire thing? I listened closely to all five minutes of the sample (the third chunk loads 49,152 bytes, from start to end of RAM). And I was surprised to hear, in a couple of places, the sound dip. What? It wasn’t doing that before.

The Falklands-era tape player had corrupted the Falklands-era tape.

Thatcher. It’s always Thatcher’s fault.

In Audacity I zoomed into the waveform where the sound dipped: flatline. Unrecoverable, by me at least. At this point, I emitted some kind of meeping noise and tweeted about throwing something and then myself out of a window.

But then I thought: I still have those earlier samples that didn’t work, sitting in the trash. I went right back to the very earliest and reimported it into Audacity. There was no dip. Then I realised I’d exported this sample first time as a stereo WAV not a mono WAV — and stereo was bad. I exported the right channel as a mono WAV, and tried that.

It worked. The game loaded.

I immediately tweeted: “Um, OK. Um. Blimey. Well. This is. Cor. Now then. Burble. *makes backup, cup of tea, squealing noise*”. It received a few worried responses. I just stared at the emulator screen.

As I write these words, I haven’t yet tried to play the game. Somewhere in my parents’ house is a complete walk-through for reviewers, sent with the tape to the software houses. Right now I can remember only one puzzle: the first one. It involves a hammer cage.

Would you, by any chance, like to play it? Here it is: the-school.tzx (apologies for Google Docs link). [Edit 2012-06-06: now available from World of Spectrum] Open it in the emulator of your choice (I’m using Fuse for Mac OS X). Press zero to delete (I’m sorry – on the Spectrum, delete was Caps Shift-zero, and for some reason I decided to “make it easier”). When a flashing block appears at the bottom right, press Return.

I warn you: it’s not particularly logical. It doesn’t have a sophisticated parser. It’s slow. I have no idea whether it’s entirely uncorrupted: it might be unsolvable. If you were at Sheredes School in the early 1980s you might know your way vaguely around. Of course, any character’s resemblance to any actual teacher or pupil of that period is entirely coincidental.

ZX Spectrum: thirty years old today. For The School, well, you just had to allow 28 years for delivery.

PS Possibly of interest: Rick Dickinson’s original industrial design sketches for the ZX Spectrum, and more.



Viewing all articles
Browse latest Browse all 6

Latest Images

Trending Articles



Latest Images