Wikipedia:Reference desk/Archives/Computing/2018 June 17

= June 17 =

What home computer systems used cassette tape before 1980?
Mel Croucher apparently broadcast some early video games over the radio in the 1970s: these must have been cassette-tape games since a radio broadcast is audio. But I'm not aware of any home computer system before 1980 that used cassette tapes. Which ones might it have been? 86.165.219.56 (talk) 20:21, 17 June 2018 (UTC)
 * Our article on magnetic tape data storage points to several possible options, including the Commodore Datasette that was really popular in the early 80's. WegianWarrior (talk) 21:49, 17 June 2018 (UTC)


 * It could have been pretty much any computer, although it would have had to be pretty sophisticated for that time (Apple II, Commodore PET, Ohio Superboard / Compukit UK101). To give a large enough audience, it would have to be either a popular model, or one capable of running a fairly "universal" language, such as BASIC. The small systems such as the KIM-1 wouldn't have either. Despite this, even the smallest systems could have cassette interfaces - the Kansas City or CUTS standards would allow data files to be moved from one system to another via broadcast radio and it was certainly done with magazine cover flexidiscs, but it's not clear what you'd do with them once they arrived. What would one of these systems make of a game written for another? Andy Dingley (talk) 22:18, 17 June 2018 (UTC)
 * It looks like it was Commodore PET software over Radio Victory, starting in 1977. Perhaps it was others too. StrayBolt (talk) 22:52, 17 June 2018 (UTC)
 * When he broadcast his "games", they were for the C=Pet (which came with a datasette drive). They weren't so much games as quizzes. It would ask a few questions. If you got them right, it would give you a phrase. You tried to be the first to call back into the show with the phrase to win. When the Zx came out, he switched to that instead of the C=64. 209.149.113.5 (talk) 16:12, 18 June 2018 (UTC)


 * The TRS-80 (1977) was one of them. Bubba73 You talkin' to me? 00:59, 18 June 2018 (UTC)


 * Some BASIC games, like Star Trek (1971 video game) could be played on most computers because they were designed for a TTY. Or they were customized for particular computers, like Apple. While many programs were published in books and magazines, it saved a lot of typing and searching for typos. StrayBolt (talk) 01:54, 18 June 2018 (UTC)


 * The Bally Astrocade (Release date 1977) had a optional module that could be inserted into the system slot. This module had a 1/8th" jack that connected to the output of a cassette deck for either saving or loading programs.  See: https://en.wikipedia.org/wiki/Bally_Astrocade  — Preceding unsigned comment added by 50.45.240.180 (talk) 11:52, 18 June 2018 (UTC)
 * I'm intrigued by this. Considering that the SNR ratio is terrible on analogue broadcast radio, how did he prevent broadcast errors? It also musta sounded pretty weird if for half an hour or so, only weird noises were broadcast that people on the receiving end had to record to a cassette live off-the-air. --2003:71:4F76:836:E846:992C:14E6:9380 (talk) 15:08, 20 June 2018 (UTC)
 * Take a look at analogue modem encoding standards, particularly for 300 baud V.21 / Bell 103 AFSK standards. What is "signal" and what is "noise"? For these early low-bitrate standards, the only signal was in the frequency, with gross shifts of it. It takes a lot of noise to disrupt this. Many of the noise sources in AM radio are simply not relevant to this simple FSK - amplitude and phase changes just aren't noticed by the receiver. But then, 300 baud is a very slow way to move programs around (it's the speed a mechanical teletype could run at). It's barely usable for typing speed, or even the 1200/75 screen reading speed. Andy Dingley (talk) 16:53, 21 June 2018 (UTC)

The Commodore PET - The whole story is described here in Mel Croucher's own book. It's an interesting story. When I read the question, I was sure that the date was wrong, or that the "radio" would turn out to be an obscure HAM Radio channel. Nope. 1977 and regular broadcast FM. He would broadcast the software well after the station's normal sign-off time, so nobody would be listening unless they were specifically looking for his software. Neat. Apparently it was part of a contest, and you had to beat the game to get clues to win the contest. ApLundell (talk) 16:09, 21 June 2018 (UTC)