A perk of writing for Hackaday comes in the vast breadth of experience represented by our fellow writers. Through our colleague [Voja Antonić] for example we’ve gained an unparalleled insight into the cutting edge of 8-bit computing in 1980s Yugoslavia, of his Galaksija home computer, and of software being broadcast over [Zoran Modli]’s Ventilator 202 radio show.
We’re strongly reminded of this by hearing of the Slovenian Radio Študent broadcasting the classic Slovenian ZX Spectrum text adventure game Kontrabant 2, at the behest of the Slovenian Computer History Museum. It’s been four decades and a lot of turbulent history, but once again 8-bit code will be heard on FM in Europe.
Some of our younger readers may never have experienced the joy of loading software from cassette, but in those days it represented a slow alternative to the eye-wateringly expensive floppy drives of the day. The software was represented as a serial bitstream translated into tones and recorded on a standard cassette recorder which was standard consumer electronics back then, and when played back through a speaker it was an ear-splitting sound with something in common with that of a modem handshake from a decade or more later. This could easily be transmitted over a radio station, and a few broadcasters tried experimental technology shows doing just that.
We haven’t heard from any listeners who managed to catch the game and run it on their Spectrum, but we hope that Slovenia’s retrocomputing community were out in force even if Audacity and a n emulator replaced the original hardware. Given that more than one hacker camp in our community has sported radio stations whether legal or not, it would be nice to hear the dulcet tones of 8-bit software on the airwaves again.
Meanwhile if cassettes are too cheap for you, feast your eyes on Sir Clive’s budget storage solution.
Thanks [Stephen Walters].
It’s fascinating how history is intertwined sometimes. Especially east vs west.
For example, I’ve read that many ZX Spectrums came from West Germany (smuggled over?), while the eastern block Z80 was the U880 – a Z80 clone from East Germany.
The latter was interesting, because it had a minor incompatibility (carry flag not set for OUTI) but was otherwise very stable.
It was built strictly according to official Zilog specs, unlike the real Z80 of the day. ;)
On other hand, many GDR computers shipped with CPUs made by Siemens from W-Germany (afaik).
Especially the 16-Bit models with 8086. The Soviet clone wasn’t nearly as readily available as the own U880, I guess?
Also, I once read that GDR engineers were kind of depressed by switching production over to make ZX Spectrum compatibles.
Their own KC8x computer line hat gotten better than the Spectrum by that point in time.
(Speaking under correction.)
“The software was represented as a serial bitstream translated into tones and recorded on a standard cassette recorder which was standard consumer electronics back then, and when played back through a speaker it was an ear-splitting sound with something in common with that of a modem handshake from a decade or more later. This could easily be transmitted over a radio station, and a few broadcasters tried experimental technology shows doing just that. ”
Something like that had been done in other poor countries, too, I believe. Like GDR.
http://de.wikipedia.org/wiki/Rem_(H%C3%B6rfunksendung)
Some related links are being mentioned by this user here:
https://circuit-board.de/forum/index.php/Thread/9738-C64-Spiele-in-den-1980er-Jahren-im-Radio-zum-Aufnehmen/?postID=223137#post223137
In GDR for example, people (kids) were barely able to buy music cassettes, even.
Even such an item was a piece of luxury.
That’s why there was the idea to use records (singles) as an alternative medium, too.
Imagine using a record player on your C64 (rare in GDR) or ZX Spectrum..
That it worked at all, is a miracle.
It’s because the datasette data format had been tried to make fool proof from vety beginning.
Back in the day, cassettes and recorders were so poor (warble, wobble, wow&flutter) and unreliable, that computer engineers had to make things extra reliable.
(Whoever had used music cassettes to store SSTV image “data” in the 70s knows that issue very well.)
That’s why a) square wave is used to store “TTL like” levels / maximum levels b) why data blocks are being repeated multiple times over and over again, slowing down loading times.
A Schmidt-trigger circuit is also being used sometimes to filter the signal levels in the datasette unit (or the computer).
The frequency pairs (tones) for data are similar to 1200 Baud Packet Radio (or RTTY, to a stretch).
So it’s no coincidence that these audio signals sound similar to acoustic couplers.
They also use Bell standard (1200/2200 Hz).
https://en.wikipedia.org/wiki/Bell_202_modem
Not just ‘poor’ countries, it happened in the UK too.
I’m pretty sure my local radio station (Piccadilly) did it and the BBC also experimented.
The BBC also distributed software via Ceefax/Teletext to accompany their computer shows on TV, you could buy a Teletext adapter which could be setup with the relevant software to download and ‘save’ the software to your local storage.
Not exactly the cheap option that though! How many 2020 thousands of pounds would that Beeb setup cost? 😂
Eventually we got a floppy drive for ours and then that got upgraded to an A3000.
Good Times.
The Beeb solution was definitely not cheap, but my local radio stations broadcast VIC20, Spectrum and C64 software to record to tape which really was.
Oh, wow. That’s amazing! There was nothing like that in my semi-rural corner of the US. Mailorder was pretty much the only way to get software. But first you needed a catalog and before that you needed to know who to even request a catalog from!
About the only way to get into the really geeky stuff was to either know someone or to buy semi-geeky magazines from the drug store then write letters in response to some of the ads found in the back.
Software broadcast on the radio for all to have… would have seemed like magic!
Also interesting might be Kansas City Standard (KCS) in this context of datasette storage.
Some RTTY terminals like the Tono 7000 supported it, too, to interface with a tape recorder and/or a microcomputer.
https://en.wikipedia.org/wiki/Kansas_City_standard
I wonder (1) if this would count as encrypted data, and (2) what the bandwidth requirements would be on 10M? I’m a ham, and wouldn’t mind trying it sometime…
KD0GZJ
Using UZ7HO “Sound Modem” or DIREWOLF modem you can send
2400b on a standard FM channel. And that is MADE for a radio, unlike
the tape. I have a “node/RMS” on a local mtn top that does it everyday.
On the radio:
https://www.amusingplanet.com/2019/04/people-once-downloaded-games-from-radio.html
and TV:
https://youtu.be/szdbKz5CyhA?si=LXWpGvqXBW9nu8Hz
(at 5:35min)
That message ‘START THE TAPE’ and following priiiiiiiiiiiipririiiiiiiii sound! Priceless :-D
I where one of those guys, whose wait to Zoran Modli anounce… “After beep sound press play and record button on your cassette recorder device”.