8 ms·

40 years later, a game for the ZX Spectrum will be again broadcast over FM radio

268 points by markostamcar 2y ago

grujicd 2y ago
This triggers a lot of nostalgic feelings. We also had that in Belgrade during 80s, in a radio show hosted by late Zoran Modli. I even recorded some of emmited games although I didn't have a computer at a time. Access to software, music, or any kind of information was hard, slow, and limited back then. Hats off to Žiga Turk and Moj Mikro magazine. That one along with Svet Kompjutera and Računari was the main source of IT knowledge for hungry minds in ex Yugoslavia.
- markostamcar 2y ago
  Nostalgic feelings is what we have been going for. We have a large amount of (also scanned) issues of Slovenian and ex-Yu magazines in our collection: https://zbirka.racunalniski-muzej.si/revije/ https://zbirka.racunalniski-muzej.si/revije/
  - vasac 2y ago
    Eh, I had all the issues of Moj Mikro while they were publishing in Serbo-Croatian, as well as all the issues of Svet Kompjutera, Računari, and PC until around 2007-2008 (Računari ceased publishing a few years later). They were all carefully packed in the basement until my mother decided to throw them all away, as who needs old stuff? And I was planning to spend my retirement days playing with the ZX Spectrum and reading stuff that I immensely enjoyed as a kid. Tough luck :)
    - grujicd 2y ago
      There are scans of these old magazines at archive.org
- gregopet 2y ago
  Žiga Turk was (at a much later time :)) also the minister of education, and he's a university professor. Just shows you that game developers can get far in life :)
surfingdino 2y ago
Is this meant to confuse the aliens by suggesting we've decided to go back to 8 bits? (Love it, btw.)
- markostamcar 2y ago
  Maybe :) Before "live to production" later tonight I tested it using a car FM transmitter adapter so things are already in motion haha.
- npongratz 2y ago
  Not just confuse them, but convince them we're not a threat, and thus not worth exterminating.
  - surfingdino 2y ago
    Don't broadcast PSSST! then. They may take it the wrong way.
apples_oranges 2y ago
Now could be the right time to put your old tape recorder on eBay (If you are in Slovenia) ;)
- supermatt 2y ago
  You can likely buy a new one on amazon for less than an old one on ebay.
- Bene592 2y ago
  You can record it with a PC. Just make sure to use a lossless format
praptak 2y ago
It should be possible to capture using a sound card.
- rwmj 2y ago
  PCM recorder is probably easiest, and the most like a tape recorder as they're widely used as replacements for dictaphones.
rwmj 2y ago
For those far away from Slovenia, is the broadcast available over the internet (I know, I know)? This link says it's not available because of "regional restrictions": https://tunein.com/radio/Radio-Student-893-s25182/ https://tunein.com/radio/Radio-Student-893-s25182/ Edit: Found a working link: https://onlineradiobox.com/si/tudent/?cs=si.tudent&played=1 https://onlineradiobox.com/si/tudent/?cs=si.tudent&played=1
- overlord_tm 2y ago
  You can also listen to stream directly on website https://radiostudent.si/ https://radiostudent.si/
  - oliwerix 2y ago
    http://kruljo.radiostudent.si:8000/ http://kruljo.radiostudent.si:8000/ is the official stream
- panki27 2y ago
  For something a bit more authentic, find a WebSDR that is located somewhere in or close to Slovenia :)
- Bene592 2y ago
  How well does this work with lossy compression? I would trust only lossless formats and analog with digital data encoded as audio, but I have zero hands-on experience with this
  - rwmj 2y ago
    The bit rate of a speccy tape recording was only about 1500 bps, and we routinely recorded on the cheapest tapes, and tape machines that were little better. I'm sure it'll be fine. Technical details for those interested: https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interface https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interfa...
    - 2y ago
Waterluvian 2y ago
What I'm most curious about is if this was always just a happy side-effect of cassette-based data storage, or if they put specific effort into making this work. Ie. by being resilient to noise before and after a broadcast, having error correction, etc.
- praptak 2y ago
  There was no error correction on ZX Spectrum, the protocol was very simple. IIRC a square wave with next bit encoded as timing of next edge, the last byte was XOR of the whole stream serving as error detection.
  - zimpenfish 2y ago
    Technical details: https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interface https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interfa... Assembly: https://worldofspectrum.net/legacy-info/spectrum-rom-load-routine/ https://worldofspectrum.net/legacy-info/spectrum-rom-load-ro... TL;DR: > A '0' bit is encoded as 2 pulses of 855 T-states each. > A '1' bit is encoded as 2 pulses of 1710 T-states each (ie. twice the length of a '0') > A 'pulse' here is either a mark or a space, so 2 pulses makes a complete square wave cycle.
- sdwr 2y ago
  I'm curious how the timing worked - what happened if you were a few seconds early to record? Was the first part of the broadcast filled with noops?
  - RetroTechie 2y ago
    ZX Spectrum tapes use a lead-in tone which the ROM code locks onto. Random noise (and data! from a previous block) before that is ignored. Zooming out, the format is: Lead-in (~4..5s usually), followed by a short header with program name & type of data that follows. A short pause. A shorter lead-in (~2s), followed by the data/program itself. Most software uses several of such blocks. Eg. a short BASIC loader, followed by a loading screen, followed by a # of KB's machine code. As far as audio tape storage goes, the ZX Spectrum system was fairly reliable & user-friendly. That's ignoring headerless blocks, speedloaders, and the many copy-protection schemes...
achairapart 2y ago
I'd like to have a listen to those waves and I'm not in Slovenia, any source on the internet? Edit: Found a short sample of a Commodore Datasette program on Wikipedia[0]. [0]: https://en.wikipedia.org/wiki/File:Datasette.ogg https://en.wikipedia.org/wiki/File:Datasette.ogg
- DeathArrow 2y ago
  Here: http://kruljo.radiostudent.si:8000/ http://kruljo.radiostudent.si:8000/
gstrike 2y ago
This is AWESOME! But, I absolutely love this time period of computing history. It was around this time (late 70s), before storage was accessible to computer nerds, that the Kansas City Standard was developed. It provided a cheap and easy way to store "large" amounts of data on standard audio cassettes which were cheap and easy to come by! It really opened up a lot of things! People no longer needed to retype their programs in to the computer every time they turned it on, it was now easy to share & copy data with friends, and it ALSO gave us the ability to broadcast programs over the radio (like this article is doing!). The original Kansas City Standard was pretty slow (300 baud), but other standards were developed shortly after (CUTS [Bob Marsh] is one) which provided more speed (1200 baud) and even backward compatibility with KCS. If anyone is interested in a the dirty details of how KCS all works, I did a series on it (https://youtu.be/6m7vDhscGzU https://youtu.be/6m7vDhscGzU). And am working on covering CUTS in the near future!
bronikowski 2y ago
I sometimes mention that our radio used to broadcast games you could tape off the air to young people and they fail to grasp the futuristic glory I experienced when I explained to myself it's like one-way modem.
- rightbyte 2y ago
  Honestly, I miss teletext so much. I was my primary news source until it was in practice abandoned. It was so nice. No pictures at all. Just text of different sizes and block art. And the wait time made you read in order once and not 'doomscrool'. The limited text length forced the writers to keep it short. My point being, one way coms are underrated.
  - A_Venom_Roll 2y ago
    In The Netherlands the teletext system of the Dutch public broadcasting system does still exist and has a loyal following. It's also available on the web [1] and as a mobile app. Even nowadays I still use it a lot myself for a quick catch up of the news. Some of the benefits: - Since space is limited, the news stories are ultra short and to the point - No ads - No "related stories" - No toxic comment sections - No misleading 'thumbnails' It doesn't take longer than a minute or two to catch up on the most important stories. [1] https://teletekst-data.nos.nl/webplus?p=100 https://teletekst-data.nos.nl/webplus?p=100
    - anthk 2y ago
      For Americans, the closest would be: https://text.npr.org https://text.npr.org https://lite.cnn.io https://lite.cnn.io gopher://magical.fish/1/news same as above, but for proxied to the web: https://gopher.floodgap.com/gopher/gw?a=gopher%3A%2F%2Fmagical.fish%2F1%2Fnews https://gopher.floodgap.com/gopher/gw?a=gopher%3A%2F%2Fmagic...
  - gorkish 2y ago
    If you are so inclined, ARRL transmits amateur radio news bulletins daily on a regular schedule[1] in the USA. The bulletins can be received with any shortwave radio that supports SSB (single sideband modulation) and decoded with a soundcard and appropriate software. Obviously, it's considerably different content, but if you are looking more for the experience of receiving and decoding a radio text bulletin, you can certainly have it! Many other teletext services[2] exist as well. [1] https://www.arrl.org/digital-transmissions https://www.arrl.org/digital-transmissions [2] https://en.wikipedia.org/wiki/List_of_teletext_services https://en.wikipedia.org/wiki/List_of_teletext_services
pjmlp 2y ago
If I remeber correctly BBC also used to do this back in the day.
- darreninthenet 2y ago
  The BBC version was a small square of "static" broadcast in the corner of the closing credits of the Micro Show and you put and square plastic box (you could get from the show, I can't remember if you had to pay for them or not) with a light sensor over that "static" square and run the special software which take the data and save it as a file. It wasn't terribly reliable but it was an interesting experiment by the BBC.
  - zerkten 2y ago
    Does the BBC still have people in place doing experiments and R&D? I recall at one point they were researching/experimenting with audio codecs. I imagine this has taken a hit with funding cuts and general short-sightedness back home.
    - noneeeed 2y ago
      It is still very much a thing. https://www.bbc.co.uk/rd https://www.bbc.co.uk/rd
    - youngNed 2y ago
      https://www.bbc.co.uk/rd/search?Type=Publications https://www.bbc.co.uk/rd/search?Type=Publications
  - DrBazza 2y ago
    The "(BBC) Micro User" used to be published monthly, and had hardware project in each edition. Towards the end there were instructions on how to build your own acoustic-coupler modem where you pushed a regular telephone into two muffled cups. I think the only or main thing you could connect to was Prestel. https://en.wikipedia.org/wiki/Prestel https://en.wikipedia.org/wiki/Prestel It was a great machine for doing early robotics too - there was an Osbourne/Usbourne book on making an arm from balsa wood.
Angostura 2y ago
I fondly remember the Pete Shelley album “XL-1” which had a final track that contained a spectrum program. You dropped the needle on the record and pressed ‘Run’ simultaneously and it would display an animated set of patterns in sync with the music - and the song lyrics
- theblazehen 2y ago
  For those curious: https://www.youtube.com/watch?v=YhKQy580STQ https://www.youtube.com/watch?v=YhKQy580STQ
  - dingaling 2y ago
    Fascinating, here's the story from the programmer: http://www.headen.com/XL1.htm http://www.headen.com/XL1.htm I'm not sure why he felt he had to write it all in machine code though, sadly he doesn't discuss that decision. Perhaps it was due to the time-dependency of the lyrics?
    - ansible 2y ago
      Without knowing the specifics of that platform, it is likely that the BASIC interpreter was not fast enough to generate the desired effects and animations.
    - Angostura 2y ago
      My guess would be quite simply to overcome memory constraints
ddmf 2y ago
There was a game on Shakin' Stevens' album where you had to hide from bats and open green doors, and even the prawn cracker like snack Skips had a game, colin the biker. Mad times.
dj_gitmo 2y ago
Was cassette tape storage more common in Europe than the U.S? I’m too young to have been around for this era, but I’ve just never seen it over here.
- Jolter 2y ago
  The Apple II was the more dominant 8-bit micro in the US. My impression is that most owners got a disk drive. Probably because the Apple II’s disk drive was a marvel of engineering, being both cheap and fast. Meanwhile, the C64 had a drive that was very expensive and very slow, and hence most Commodore owners would just use the included cassette player. Perhaps it was similar with the Spectrum? It also makes some sense that users in the East Bloc would have trouble affording expensive hardware.
  - gregopet 2y ago
    Interestingly enough, the plot of the game being broadcast was (if I remember correctly) about smuggling a new computer from the west. It was loaded with puns at the system (e.g. one of the locations was a government building and you had to navigate through its loopholes).
  - NikkiA 2y ago
    The spectrum didn't have an official (**) floppy disk add-on, the official mass storage upgrade* was the microdrive, which was a 100kB tape loop format - an improvement on cassettes, but not by much. As a result, there was a wide range of unofficial floppy disk addons, which then brought the issue that there were so many competing products that supporting them all was near impossible and hardly any commercial software bothered. Post main-popularity, most people settled on the Beta Disc / Beta 128 from Technology Research as being the main unofficial standard, somewhat bolstered by it being adopted in eastern europe and russia, but during the main popularity period, even it had really poor market share in the UK. * There was also the cartridges for the Interface 2, but that's a different beast entirely and they were even less common than the Interface 1 + microdrive. ** of course there was the Spectrum +3 near the end of the spectrum's life which had a built-in 3" amstrad drive, which saw reasonable commercial support, but it was long after the main portion of the spectrum's popularity, and at a time when the ST and Amiga were beginning to dominate.
DrBazza 2y ago
Back in the day, there were magazines that had a flexible plastic LP/single (aka 'vinyl'), that you'd play on your stereo, and record to cassette, and load into the computer. Coincidentally, it's this - https://www.youtube.com/watch?v=1FePROXUG6E https://www.youtube.com/watch?v=1FePROXUG6E
- qingcharles 2y ago
  Me: going through the racks of magazines trying to find a record without a crease in it.
  - DrBazza 2y ago
    Yes!
gregopet 2y ago
A friend of mine had faulty wiring in his house, the electricity would go out for a few brief moments whenever someone would ring his house bell. He would stand in front of his house when ZX Spectrum games were being broadcast so nobody would ring and interrupt his recorder :)
- jprd 2y ago
  This is so great! Reminds me of policing the phone line so someone didn't blow up my BBS Kermit downloads.
- harryf 2y ago
  For me it was my mum turning on the vacuum cleaner would cause a spike that could reboot the Spectrum 48K. The 128 model had a better power supply as I remember. Also the ZX81 I had before that (think I was 8 at the time) was extremely sensitive to the state of the current in the house...
ajsnigrutin 2y ago
It's funny how we used to have games over radio waves (this, article, but 40 yars ago), then went through a bunch of other media (cartridges, floppies, cds, dvds, blurays,...) and then came back to games over radio waves (download via mobile network).
ochrist 2y ago
Back in the eighties the Dutch radio network NOS broadcast programs for all types of home computers. They even invented a common BASIC dialect for this to work: BASICODE https://archive.org/details/BASICODE2Manual https://archive.org/details/BASICODE2Manual This was sent on AM, so it was available in other European countries as well.
chairleader 2y ago
Out of curiosity, are there Linux tools to go from binary files to audio and back again? i.e `cat archive.zip | faxify -wav > archive.zip.wav`
- anthk 2y ago
  Minimodem Encode to opus: cat foo.zip | minimodem --tx -r 300 -f out.flac opusenc --bitrate 64 out.flac out.opus Decode from opus: minimodem --rx -r 300 -f out.opus > foo2.zip
  - chairleader 2y ago
    fantastic, thanks!
gregopet 2y ago
The user manual is also quite awesome :) Here's the bit about copy protection (translation is mine): Programs cannot be copy-protected successfully. KONTRABANT 2 is protected only insofar as not just anyone can look at its databases. Therefore you could copy it to whomever you wish. Know that by doing so you will be nipping Yugoslavia's young software industry in the bud and hurt us, the enthusiasts who are writing it. You will also be hurting yourself. Programs will become more expensive due to smaller sales or won't come to exist in the first place. Copying programs is hurting everything ALL of us computer folk have fought for. We've already achieved that anyone can buy a modest computer legally without humiliating themselves at a border crossing while YOU can help us breathe our local soul into these machines.
- gregopet 2y ago
  ..and in the troubleshooting section: Don't forget the first law of computer science: "Is it turned on?"
tombert 2y ago
It's a bit before my time, and tape based games never really caught on in the US as far as I'm aware, but I've always been kind of fascinated by storing programs in audio. There's something bizarrely cool about the idea of taking something designed for an analog medium and using it for something sort of definitionally not analog. It was traditionally cassette tapes, but I saw a YouTube video where some companies distributed games on CDs, and there's something kind of weird and anachronistic about being able to play a ZX Spectrum game off a CD; the program is going from Digital (being written) -> analog (converted to audio signals) -> digital (put on a CD) -> analog (back to audio) -> digital (read by the computer). People can be pretty clever sometimes.
- nilamo 2y ago
  The PS1 used CDs. Many games could be dropped into a cd player, and if you skip the first track (the data track), the rest of the game's music/audio could be played.
  - magnusmundus 2y ago
    It was possible to do the same with some PC games! I have fond memories of listening to the soundtracks of Driver, and Knights and Merchants, on my little stereo.
    - grujicd 2y ago
      Cassette tapes for Atari 800XL used just a single channel for data. The other one could have music and you would listen to it during game loading.
    - tombert 2y ago
      Yeah, X-Wing vs Tie Fighter had a lot of the popular Star Wars music in redbook audio so it would work fine in a CD player, a fact that I was super excited to find out when I was a kid playing with my action figures.
- SillyUsername 2y ago
  Dialup modem did the same thing but with more efficient protocol and error control via a network stack. ADSL also took a step further and used the shielding on copper cables to attain higher (inaudible) frequencies. The tech in some form is still about this is just the granddaddy version :D
ACV001 2y ago
I remember how proud of myself I was when I connected the computer's audio inputs to a standard casette player with speed up function so I could load the games twice as fast.
jimmytucson 2y ago
This is so cool! Does anyone know how the data is encoded in the signal? Is it just data for the game that's transmitted (and the logic resides on the ZX Spectrum) or is logic also transmitted?
- opencl 2y ago
  The format is very simple, basically a square wave with different pulse widths for 1s and 0s [1]. Spectrum software was typically sold on audio cassettes and the radio broadcasts are the exact same format, typically people would record the broadcasts to cassette. The loader program in ROM just copies all the data from tape (or radio) into RAM so yes any game logic would be included in that. [1] https://en.m.wikipedia.org/wiki/ZX_Spectrum_software https://en.m.wikipedia.org/wiki/ZX_Spectrum_software
nlawalker 2y ago
FYI, there's a fun indie game from 2016 on all the major platforms called Lumo[1] that's an homage to the isometric puzzle/adventure games of the ZX Spectrum era. I didn't really know anything about said era, as it was mostly before my time, but I ended up looking up a bunch of stuff as I played and it gave me an appreciation for it. The director/developer has a full walkthrough with commentary on YouTube where he explains everything.[2] [1] https://store.steampowered.com/app/345480/Lumo/ https://store.steampowered.com/app/345480/Lumo/ [2] https://www.youtube.com/playlist?list=PLHaRTzqB6QC9uzqnwNViwZB0Gtsg_Q1Sm https://www.youtube.com/playlist?list=PLHaRTzqB6QC9uzqnwNViw...
anthk 2y ago
With minimodem and some streaming service you can mimic that, but as a client you need to cache the data with mplayer or mpv to avoid losing data: http://www.whence.com/minimodem/ http://www.whence.com/minimodem/
anthk 2y ago
As a silly test, I encoded the Spanish versions of the Sherlock Holmes' volumes (XZ compressed each one) to FLAC with minimodem --tx 300, and later I converted them to Opus at 64 Kbps. Each file weighted less than 30MB, not bad at all. The raw WAV files were around 400MB each. The files were re-read back with minimodem --rx at the same rate and dumped back to an XZ file, the sha512sum matched the originals.

268 points by markostamcar 2y ago

This triggers a lot of nostalgic feelings. We also had that in Belgrade during 80s, in a radio show hosted by late Zoran Modli. I even recorded some of emmited games although I didn't have a computer at a time. Access to software, music, or any kind of information was hard, slow, and limited back then. Hats off to Žiga Turk and Moj Mikro magazine. That one along with Svet Kompjutera and Računari was the main source of IT knowledge for hungry minds in ex Yugoslavia.

markostamcar 2y ago
Nostalgic feelings is what we have been going for. We have a large amount of (also scanned) issues of Slovenian and ex-Yu magazines in our collection: https://zbirka.racunalniski-muzej.si/revije/ https://zbirka.racunalniski-muzej.si/revije/
- vasac 2y ago
  Eh, I had all the issues of Moj Mikro while they were publishing in Serbo-Croatian, as well as all the issues of Svet Kompjutera, Računari, and PC until around 2007-2008 (Računari ceased publishing a few years later). They were all carefully packed in the basement until my mother decided to throw them all away, as who needs old stuff? And I was planning to spend my retirement days playing with the ZX Spectrum and reading stuff that I immensely enjoyed as a kid. Tough luck :)
  - grujicd 2y ago
    There are scans of these old magazines at archive.org
gregopet 2y ago
Žiga Turk was (at a much later time :)) also the minister of education, and he's a university professor. Just shows you that game developers can get far in life :)

surfingdino 2y ago

Is this meant to confuse the aliens by suggesting we've decided to go back to 8 bits? (Love it, btw.)

markostamcar 2y ago
Maybe :) Before "live to production" later tonight I tested it using a car FM transmitter adapter so things are already in motion haha.
npongratz 2y ago
Not just confuse them, but convince them we're not a threat, and thus not worth exterminating.
- surfingdino 2y ago
  Don't broadcast PSSST! then. They may take it the wrong way.

apples_oranges 2y ago

Now could be the right time to put your old tape recorder on eBay (If you are in Slovenia) ;)

supermatt 2y ago
You can likely buy a new one on amazon for less than an old one on ebay.
Bene592 2y ago
You can record it with a PC. Just make sure to use a lossless format

praptak 2y ago

It should be possible to capture using a sound card.

rwmj 2y ago
PCM recorder is probably easiest, and the most like a tape recorder as they're widely used as replacements for dictaphones.

rwmj 2y ago

For those far away from Slovenia, is the broadcast available over the internet (I know, I know)? This link says it's not available because of "regional restrictions": https://tunein.com/radio/Radio-Student-893-s25182/ https://tunein.com/radio/Radio-Student-893-s25182/ Edit: Found a working link: https://onlineradiobox.com/si/tudent/?cs=si.tudent&played=1 https://onlineradiobox.com/si/tudent/?cs=si.tudent&played=1

overlord_tm 2y ago
You can also listen to stream directly on website https://radiostudent.si/ https://radiostudent.si/
- oliwerix 2y ago
  http://kruljo.radiostudent.si:8000/ http://kruljo.radiostudent.si:8000/ is the official stream
panki27 2y ago
For something a bit more authentic, find a WebSDR that is located somewhere in or close to Slovenia :)
Bene592 2y ago
How well does this work with lossy compression? I would trust only lossless formats and analog with digital data encoded as audio, but I have zero hands-on experience with this
- rwmj 2y ago
  The bit rate of a speccy tape recording was only about 1500 bps, and we routinely recorded on the cheapest tapes, and tape machines that were little better. I'm sure it'll be fine. Technical details for those interested: https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interface https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interfa...
  - 2y ago

Waterluvian 2y ago

What I'm most curious about is if this was always just a happy side-effect of cassette-based data storage, or if they put specific effort into making this work. Ie. by being resilient to noise before and after a broadcast, having error correction, etc.

praptak 2y ago
There was no error correction on ZX Spectrum, the protocol was very simple. IIRC a square wave with next bit encoded as timing of next edge, the last byte was XOR of the whole stream serving as error detection.
- zimpenfish 2y ago
  Technical details: https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interface https://sinclair.wiki.zxnet.co.uk/wiki/Spectrum_tape_interfa... Assembly: https://worldofspectrum.net/legacy-info/spectrum-rom-load-routine/ https://worldofspectrum.net/legacy-info/spectrum-rom-load-ro... TL;DR: > A '0' bit is encoded as 2 pulses of 855 T-states each. > A '1' bit is encoded as 2 pulses of 1710 T-states each (ie. twice the length of a '0') > A 'pulse' here is either a mark or a space, so 2 pulses makes a complete square wave cycle.
sdwr 2y ago
I'm curious how the timing worked - what happened if you were a few seconds early to record? Was the first part of the broadcast filled with noops?
- RetroTechie 2y ago
  ZX Spectrum tapes use a lead-in tone which the ROM code locks onto. Random noise (and data! from a previous block) before that is ignored. Zooming out, the format is: Lead-in (~4..5s usually), followed by a short header with program name & type of data that follows. A short pause. A shorter lead-in (~2s), followed by the data/program itself. Most software uses several of such blocks. Eg. a short BASIC loader, followed by a loading screen, followed by a # of KB's machine code. As far as audio tape storage goes, the ZX Spectrum system was fairly reliable & user-friendly. That's ignoring headerless blocks, speedloaders, and the many copy-protection schemes...

achairapart 2y ago

I'd like to have a listen to those waves and I'm not in Slovenia, any source on the internet? Edit: Found a short sample of a Commodore Datasette program on Wikipedia[0]. [0]: https://en.wikipedia.org/wiki/File:Datasette.ogg https://en.wikipedia.org/wiki/File:Datasette.ogg

DeathArrow 2y ago
Here: http://kruljo.radiostudent.si:8000/ http://kruljo.radiostudent.si:8000/

gstrike 2y ago

This is AWESOME! But, I absolutely love this time period of computing history. It was around this time (late 70s), before storage was accessible to computer nerds, that the Kansas City Standard was developed. It provided a cheap and easy way to store "large" amounts of data on standard audio cassettes which were cheap and easy to come by! It really opened up a lot of things! People no longer needed to retype their programs in to the computer every time they turned it on, it was now easy to share & copy data with friends, and it ALSO gave us the ability to broadcast programs over the radio (like this article is doing!). The original Kansas City Standard was pretty slow (300 baud), but other standards were developed shortly after (CUTS [Bob Marsh] is one) which provided more speed (1200 baud) and even backward compatibility with KCS. If anyone is interested in a the dirty details of how KCS all works, I did a series on it (https://youtu.be/6m7vDhscGzU https://youtu.be/6m7vDhscGzU). And am working on covering CUTS in the near future!

bronikowski 2y ago

I sometimes mention that our radio used to broadcast games you could tape off the air to young people and they fail to grasp the futuristic glory I experienced when I explained to myself it's like one-way modem.

rightbyte 2y ago
Honestly, I miss teletext so much. I was my primary news source until it was in practice abandoned. It was so nice. No pictures at all. Just text of different sizes and block art. And the wait time made you read in order once and not 'doomscrool'. The limited text length forced the writers to keep it short. My point being, one way coms are underrated.
- A_Venom_Roll 2y ago
  In The Netherlands the teletext system of the Dutch public broadcasting system does still exist and has a loyal following. It's also available on the web [1] and as a mobile app. Even nowadays I still use it a lot myself for a quick catch up of the news. Some of the benefits: - Since space is limited, the news stories are ultra short and to the point - No ads - No "related stories" - No toxic comment sections - No misleading 'thumbnails' It doesn't take longer than a minute or two to catch up on the most important stories. [1] https://teletekst-data.nos.nl/webplus?p=100 https://teletekst-data.nos.nl/webplus?p=100
  - anthk 2y ago
    For Americans, the closest would be: https://text.npr.org https://text.npr.org https://lite.cnn.io https://lite.cnn.io gopher://magical.fish/1/news same as above, but for proxied to the web: https://gopher.floodgap.com/gopher/gw?a=gopher%3A%2F%2Fmagical.fish%2F1%2Fnews https://gopher.floodgap.com/gopher/gw?a=gopher%3A%2F%2Fmagic...
- gorkish 2y ago
  If you are so inclined, ARRL transmits amateur radio news bulletins daily on a regular schedule[1] in the USA. The bulletins can be received with any shortwave radio that supports SSB (single sideband modulation) and decoded with a soundcard and appropriate software. Obviously, it's considerably different content, but if you are looking more for the experience of receiving and decoding a radio text bulletin, you can certainly have it! Many other teletext services[2] exist as well. [1] https://www.arrl.org/digital-transmissions https://www.arrl.org/digital-transmissions [2] https://en.wikipedia.org/wiki/List_of_teletext_services https://en.wikipedia.org/wiki/List_of_teletext_services

pjmlp 2y ago

If I remeber correctly BBC also used to do this back in the day.

darreninthenet 2y ago
The BBC version was a small square of "static" broadcast in the corner of the closing credits of the Micro Show and you put and square plastic box (you could get from the show, I can't remember if you had to pay for them or not) with a light sensor over that "static" square and run the special software which take the data and save it as a file. It wasn't terribly reliable but it was an interesting experiment by the BBC.
- zerkten 2y ago
  Does the BBC still have people in place doing experiments and R&D? I recall at one point they were researching/experimenting with audio codecs. I imagine this has taken a hit with funding cuts and general short-sightedness back home.
  - noneeeed 2y ago
    It is still very much a thing. https://www.bbc.co.uk/rd https://www.bbc.co.uk/rd
  - youngNed 2y ago
    https://www.bbc.co.uk/rd/search?Type=Publications https://www.bbc.co.uk/rd/search?Type=Publications
- DrBazza 2y ago
  The "(BBC) Micro User" used to be published monthly, and had hardware project in each edition. Towards the end there were instructions on how to build your own acoustic-coupler modem where you pushed a regular telephone into two muffled cups. I think the only or main thing you could connect to was Prestel. https://en.wikipedia.org/wiki/Prestel https://en.wikipedia.org/wiki/Prestel It was a great machine for doing early robotics too - there was an Osbourne/Usbourne book on making an arm from balsa wood.

Angostura 2y ago

I fondly remember the Pete Shelley album “XL-1” which had a final track that contained a spectrum program. You dropped the needle on the record and pressed ‘Run’ simultaneously and it would display an animated set of patterns in sync with the music - and the song lyrics

theblazehen 2y ago
For those curious: https://www.youtube.com/watch?v=YhKQy580STQ https://www.youtube.com/watch?v=YhKQy580STQ
- dingaling 2y ago
  Fascinating, here's the story from the programmer: http://www.headen.com/XL1.htm http://www.headen.com/XL1.htm I'm not sure why he felt he had to write it all in machine code though, sadly he doesn't discuss that decision. Perhaps it was due to the time-dependency of the lyrics?
  - ansible 2y ago
    Without knowing the specifics of that platform, it is likely that the BASIC interpreter was not fast enough to generate the desired effects and animations.
  - Angostura 2y ago
    My guess would be quite simply to overcome memory constraints

ddmf 2y ago

There was a game on Shakin' Stevens' album where you had to hide from bats and open green doors, and even the prawn cracker like snack Skips had a game, colin the biker. Mad times.

dj_gitmo 2y ago

Was cassette tape storage more common in Europe than the U.S? I’m too young to have been around for this era, but I’ve just never seen it over here.

Jolter 2y ago
The Apple II was the more dominant 8-bit micro in the US. My impression is that most owners got a disk drive. Probably because the Apple II’s disk drive was a marvel of engineering, being both cheap and fast. Meanwhile, the C64 had a drive that was very expensive and very slow, and hence most Commodore owners would just use the included cassette player. Perhaps it was similar with the Spectrum? It also makes some sense that users in the East Bloc would have trouble affording expensive hardware.
- gregopet 2y ago
  Interestingly enough, the plot of the game being broadcast was (if I remember correctly) about smuggling a new computer from the west. It was loaded with puns at the system (e.g. one of the locations was a government building and you had to navigate through its loopholes).
- NikkiA 2y ago
  The spectrum didn't have an official (**) floppy disk add-on, the official mass storage upgrade* was the microdrive, which was a 100kB tape loop format - an improvement on cassettes, but not by much. As a result, there was a wide range of unofficial floppy disk addons, which then brought the issue that there were so many competing products that supporting them all was near impossible and hardly any commercial software bothered. Post main-popularity, most people settled on the Beta Disc / Beta 128 from Technology Research as being the main unofficial standard, somewhat bolstered by it being adopted in eastern europe and russia, but during the main popularity period, even it had really poor market share in the UK. * There was also the cartridges for the Interface 2, but that's a different beast entirely and they were even less common than the Interface 1 + microdrive. ** of course there was the Spectrum +3 near the end of the spectrum's life which had a built-in 3" amstrad drive, which saw reasonable commercial support, but it was long after the main portion of the spectrum's popularity, and at a time when the ST and Amiga were beginning to dominate.

DrBazza 2y ago

Back in the day, there were magazines that had a flexible plastic LP/single (aka 'vinyl'), that you'd play on your stereo, and record to cassette, and load into the computer. Coincidentally, it's this - https://www.youtube.com/watch?v=1FePROXUG6E https://www.youtube.com/watch?v=1FePROXUG6E

qingcharles 2y ago
Me: going through the racks of magazines trying to find a record without a crease in it.
- DrBazza 2y ago
  Yes!

gregopet 2y ago

A friend of mine had faulty wiring in his house, the electricity would go out for a few brief moments whenever someone would ring his house bell. He would stand in front of his house when ZX Spectrum games were being broadcast so nobody would ring and interrupt his recorder :)

jprd 2y ago
This is so great! Reminds me of policing the phone line so someone didn't blow up my BBS Kermit downloads.
harryf 2y ago
For me it was my mum turning on the vacuum cleaner would cause a spike that could reboot the Spectrum 48K. The 128 model had a better power supply as I remember. Also the ZX81 I had before that (think I was 8 at the time) was extremely sensitive to the state of the current in the house...

ajsnigrutin 2y ago

It's funny how we used to have games over radio waves (this, article, but 40 yars ago), then went through a bunch of other media (cartridges, floppies, cds, dvds, blurays,...) and then came back to games over radio waves (download via mobile network).

ochrist 2y ago

Back in the eighties the Dutch radio network NOS broadcast programs for all types of home computers. They even invented a common BASIC dialect for this to work: BASICODE https://archive.org/details/BASICODE2Manual https://archive.org/details/BASICODE2Manual This was sent on AM, so it was available in other European countries as well.

chairleader 2y ago

Out of curiosity, are there Linux tools to go from binary files to audio and back again? i.e `cat archive.zip | faxify -wav > archive.zip.wav`

anthk 2y ago
Minimodem Encode to opus: cat foo.zip | minimodem --tx -r 300 -f out.flac opusenc --bitrate 64 out.flac out.opus Decode from opus: minimodem --rx -r 300 -f out.opus > foo2.zip
- chairleader 2y ago
  fantastic, thanks!

gregopet 2y ago

The user manual is also quite awesome :) Here's the bit about copy protection (translation is mine): Programs cannot be copy-protected successfully. KONTRABANT 2 is protected only insofar as not just anyone can look at its databases. Therefore you could copy it to whomever you wish. Know that by doing so you will be nipping Yugoslavia's young software industry in the bud and hurt us, the enthusiasts who are writing it. You will also be hurting yourself. Programs will become more expensive due to smaller sales or won't come to exist in the first place. Copying programs is hurting everything ALL of us computer folk have fought for. We've already achieved that anyone can buy a modest computer legally without humiliating themselves at a border crossing while YOU can help us breathe our local soul into these machines.

gregopet 2y ago
..and in the troubleshooting section: Don't forget the first law of computer science: "Is it turned on?"

tombert 2y ago

It's a bit before my time, and tape based games never really caught on in the US as far as I'm aware, but I've always been kind of fascinated by storing programs in audio. There's something bizarrely cool about the idea of taking something designed for an analog medium and using it for something sort of definitionally not analog. It was traditionally cassette tapes, but I saw a YouTube video where some companies distributed games on CDs, and there's something kind of weird and anachronistic about being able to play a ZX Spectrum game off a CD; the program is going from Digital (being written) -> analog (converted to audio signals) -> digital (put on a CD) -> analog (back to audio) -> digital (read by the computer). People can be pretty clever sometimes.

nilamo 2y ago
The PS1 used CDs. Many games could be dropped into a cd player, and if you skip the first track (the data track), the rest of the game's music/audio could be played.
- magnusmundus 2y ago
  It was possible to do the same with some PC games! I have fond memories of listening to the soundtracks of Driver, and Knights and Merchants, on my little stereo.
  - grujicd 2y ago
    Cassette tapes for Atari 800XL used just a single channel for data. The other one could have music and you would listen to it during game loading.
  - tombert 2y ago
    Yeah, X-Wing vs Tie Fighter had a lot of the popular Star Wars music in redbook audio so it would work fine in a CD player, a fact that I was super excited to find out when I was a kid playing with my action figures.
SillyUsername 2y ago
Dialup modem did the same thing but with more efficient protocol and error control via a network stack. ADSL also took a step further and used the shielding on copper cables to attain higher (inaudible) frequencies. The tech in some form is still about this is just the granddaddy version :D

ACV001 2y ago

I remember how proud of myself I was when I connected the computer's audio inputs to a standard casette player with speed up function so I could load the games twice as fast.

jimmytucson 2y ago

This is so cool! Does anyone know how the data is encoded in the signal? Is it just data for the game that's transmitted (and the logic resides on the ZX Spectrum) or is logic also transmitted?

opencl 2y ago
The format is very simple, basically a square wave with different pulse widths for 1s and 0s [1]. Spectrum software was typically sold on audio cassettes and the radio broadcasts are the exact same format, typically people would record the broadcasts to cassette. The loader program in ROM just copies all the data from tape (or radio) into RAM so yes any game logic would be included in that. [1] https://en.m.wikipedia.org/wiki/ZX_Spectrum_software https://en.m.wikipedia.org/wiki/ZX_Spectrum_software

nlawalker 2y ago

FYI, there's a fun indie game from 2016 on all the major platforms called Lumo[1] that's an homage to the isometric puzzle/adventure games of the ZX Spectrum era. I didn't really know anything about said era, as it was mostly before my time, but I ended up looking up a bunch of stuff as I played and it gave me an appreciation for it. The director/developer has a full walkthrough with commentary on YouTube where he explains everything.[2] [1] https://store.steampowered.com/app/345480/Lumo/ https://store.steampowered.com/app/345480/Lumo/ [2] https://www.youtube.com/playlist?list=PLHaRTzqB6QC9uzqnwNViwZB0Gtsg_Q1Sm https://www.youtube.com/playlist?list=PLHaRTzqB6QC9uzqnwNViw...

anthk 2y ago

With minimodem and some streaming service you can mimic that, but as a client you need to cache the data with mplayer or mpv to avoid losing data: http://www.whence.com/minimodem/ http://www.whence.com/minimodem/

anthk 2y ago

As a silly test, I encoded the Spanish versions of the Sherlock Holmes' volumes (XZ compressed each one) to FLAC with minimodem --tx 300, and later I converted them to Opus at 64 Kbps. Each file weighted less than 30MB, not bad at all. The raw WAV files were around 400MB each. The files were re-read back with minimodem --rx at the same rate and dumped back to an XZ file, the sha512sum matched the originals.