cassette deck as long time data storage was a thing in 1987 - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: February 12, 2023, 01:45:57 pm
content: i have never even heard about cassette decs used as datastorage beforeand then i score a stack of those unints,so i think it is only fair to share with youhttps://youtu.be/kTxlk-7OyLcplease comment if you used or have seen anything like this before

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 12, 2023, 02:39:36 pm
content: Was used in the early 90's at the aerospace firm I worked at to back up desktop computers. The "real" computing systems used better systems.I think these things were widely used in small to medium businesses who joined the PC revolution in the eighties and somewhere along the line realized that better data backup than a box of floppies was needed. The technology window didn't last long.

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 12, 2023, 03:58:02 pm
content: My first thought was "Yeah well, all hobby computers (Tandy, Commodore, BBC) of that era used tape recorders to store data". Then I saw the YT

author: iMo
author_rank: Super Contributor
timestamp: February 12, 2023, 04:21:29 pm
content: I was using cassette deck as the data storage for years (early 80ties)My ZX-81, ZX_Spectrum, PC-1251 and my diy 8085 sbc all worked with it.To load a sw into the 48kB ZX-Spectrum took perhaps 10-15minutes or more.. Copying a single game took a half an hour easily (from a cassette -> the ZX -> a cassette)..

author: Neepa
author_rank: Regular Contributor
timestamp: February 12, 2023, 04:22:35 pm
content: So these modified audio tape drives store digital data as an analog track on normal tapes?Tbh I always thought the microcomputer variant did that too. As the cheapest most affordable way to store data for the 80ies. And not the DAT Audio Tape approach.

author: MarkL
author_rank: Unknown
timestamp: February 12, 2023, 04:23:45 pm
content: Other than the hobby-level cassette storage that came with the TRS-80 and previous S-100 based computers, I used a Wang 2200 that had a built-in cassette storage drive, around 1977 or so:https://history-computer.com/wang-2200-guide/If I recall, the data cassettes were regular high-quality cassettes, but had no leader. I remember taking apart regular audio cassettes and modifying them by removing the leader, and I think there was something else on the cassette that the transport needed to see before it would recognize it. It might have been an extra hole in the cassette case somewhere.

author: iMo
author_rank: Super Contributor
timestamp: February 12, 2023, 04:26:52 pm
content: We were using standard cassette decks and "normal" tapes. Nothing special..I saw some people did hacks, like direct recording of a TTL level via a resistor into the head, it worked too..

author: mariush
author_rank: Super Contributor
timestamp: February 12, 2023, 04:48:08 pm
content: While watching the video, I was wondering how expensive it would have been to replace the cassette tape with a bunch of eeprom chips or some other kind of storage?I suspect it would have been orders of magnitude more expensive ... couldn't find any old catalogues with chip prices.

author: iMo
author_rank: Super Contributor
timestamp: February 12, 2023, 04:54:38 pm
content: A cassette was the standard for sharing and storing the sw in early 80ties (when talking small computing). The floppy drives were expensive and came in mid/late 80ties, afaik. There was none other option how to store say 40kB of code (a game) at that time (when talking small computing). An EPROM for example the "2732" 4kB large cost $10-$20 at that time as I can remember.

author: wasedadoc
author_rank: Super Contributor
timestamp: February 12, 2023, 05:04:30 pm
content: Clearly it wasn't the earliest but I made a simple interface for my Science of Cambridge MK14 to store data on cassette tape and that was a year or two before the Sinclair ZX80 in 1979. At that time there were no eeproms. UV erasable EPROMs did exist. Recognisable by the transparent window in the chip body over the die. 32 kbyte and 64 kbyte were the largest available around that time. Sinclair used UV erasable EPROMs in plug-in cartridges for the Z88 portable computer launched in 1987. Psion also used UV EPROMs in plug-in Datapacks for the Psion Organiser II.

author: iMo
author_rank: Super Contributor
timestamp: February 12, 2023, 05:15:26 pm
content: The small computers around 1980+ had the "os" and the Basic in a ROM, like 8-16kB large. I was replacing the ATARI TOS (in 87 or 88) in my ATARI 520STM (that was a BIG machine) with 6x 27512 EPROMs (3264kB), the 6 EPROMs cost something like 250DM at that time.And you had to build your own EPROM programmer, of course (and an UV eraser as well)..

author: wasedadoc
author_rank: Super Contributor
timestamp: February 12, 2023, 05:18:12 pm
content: Quote from: imo on February 12, 2023, 05:15:26 pm32kbyte EPROMs were 27256. 27512s were 64kbyte.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 12, 2023, 08:32:39 pm
content: The Comodore PETs, VC20 and C64 incluced an interface for cassett storage. AFAIR a few more early home computers used that too. One could use normal audio tapes and even recorders with a more or less simple adapter cable. There was also a rather cheap drive for the C64 / VC20. The capacitoy was not that bad for the time, especially when using a higher data density than the original comodore format.The 1500 Baud would be around 1 Mbytes to a 90 min tape. Chances are one could get a higher density.For the costs of EPROM storage it really depended on time - the initial proces where quite high, but later got reasonable cheap. Writing the data needed extra effort.Chanes are there were systems to log data to EPROM too.The shown system was for really slow data rates - more like weather, water levels or similar. Science experiments sometimes produce a lot of data, especially if done like the early particle physics: record as much raw data as possible and do the processing later. So if one finds something unusual one hopefully has enough data - likely most will be ignored as nothing interresting or bad happend. I remember setting up a relatively small system to record some 1 Gbytes of data over night - normally just looking at maybe 10% of that later.

author: tooki
author_rank: Super Contributor
timestamp: February 12, 2023, 11:30:38 pm
content: Quote from: Neepa on February 12, 2023, 04:22:35 pmWell yes, they do. Sounds basically like a dialup modem.Quote from: Neepa on February 12, 2023, 04:22:35 pmDAT is essentially a really, really miniaturized VCR. A marvel of engineering, really. Mechanically more complicated, but of course that’s to enable a vastly higher data density and data rate. (Around 1.5Mbps on DAT, vs around 300bps on audio cassette, so around 5000 times as high, on tape of the same width.)Anyway, to everyone bringing up the well-known home computers with cassette storage: you’ve missed the point here, which is that there was adedicated version of the cassette formatfor data, with different cassettes and different drives that don’t work like audio cassette decks.

author: BrianHG
author_rank: Super Contributor
timestamp: February 13, 2023, 01:15:39 am
content: I thought DAT tapes got something like 80gb on a 180meter tape, or, something like 7.5 megabit / sec, not 1.5 megabit per sec.I wonder how fast the Digital 8 format was. It's tape size was close, slightly bigger than the DAT format.

author: tooki
author_rank: Super Contributor
timestamp: February 13, 2023, 03:09:59 am
content: Quote from: BrianHG on February 13, 2023, 01:15:39 amYou’re probably thinking of some later version of DDS, the data version of DAT. But DAT itself (i.e. audio) was up to 48kHz x 2ch x 16bit ≈ 1.5Mbps. (It also supported 44.1kHz and 32kHz sample rates.)Quote from: BrianHG on February 13, 2023, 01:15:39 amDigital8 was simply the standard DV codec recorded onto Hi8 tape. So fixed 25Mbps.8mm videocassettes (Video8, Hi8, Digital8) are appreciably larger than DAT in every dimension:DAT: 73 × 54 × 10.5 mm8mm: 95 × 62.5 × 15 mm(Note the difference in thickness in particular.)As for the width of the tape itself (since you did say “tape size”, not “cassette size”), DAT is 0.15” (3.81mm), Video8/Hi8/Digital8 are 8mm.

author: cantata.tech
author_rank: Regular Contributor
timestamp: February 13, 2023, 05:28:44 am
content: I have a Sony TC-2860 that I bought in Japan sometime back.I wouldn't advise using the tape. Too slow and too little data.What I'm planning to do is run a Raspberry-pi with some 1/2TB drives and use it as a NAS server.The cases are beautiful and don't deserve to go in the bin.All the modern computing equipment required will fit in the battery bay.An ESP32 fits in the cassette bay.This is how I'm approaching it.

author: Haenk
author_rank: Super Contributor
timestamp: February 13, 2023, 08:42:47 am
content: CompuCorp used an external tape deck in the early 70s, around 1973.(Didn't Wang use a similar system as well?)Also, I remember a VHS tape system for the Amiga, AFAIR it never made it to market though.

author: TurboTom
author_rank: Super Contributor
timestamp: February 13, 2023, 09:06:23 am
content: Quote from: BrianHG on February 13, 2023, 01:15:39 am... I've got fond memories of "playing around" with Sparc Stations and Exabyte Video 8 Streamers that we picked up for close to nothing at an electronics scrapper as university students in the early nineties... The trips to the scrapper with some friends were virtually better than Christmas, you never new what you'ld find -- we must have picked up a few gigabyte of RAM in total (the 30-Pin SIMM variety) which provided a nice financial "push" to us "always-broke" pals. There was scientific gear, lithosetters, drum scanners, obviously computers, lasers, you name it, you'll find it... Of course, we had to pay a little for the stuff, but knowing what it is usually meant one could make some bargain from it...Curiously, what's still left over today from this "hunter-gatherer" times (among some other bits and pieces) is the same Teac tape drive mechanism that the OP showed, yet with the piggyback PCB still present (NOS condition...)!

author: Krotow
author_rank: Regular Contributor
timestamp: February 13, 2023, 10:31:25 am
content: Cassette deck tapes as storage definitely was a thing for home computer hobyists in eighties and at begin of nineties. I too used this storage method often to store programs and games for small computers like ZX Spectrum Soviet clone, Радио-86РК and БК-0010. Stereo cassete decks though was not the best ones due to signal difference between channels. Mono cassete recorders gave better results. Industrial storage on cassette deck tapes however I see at first timeVHS tapes also was used as inexpensive storage method. Those was not so popular though due to particularly expensive hardware prices in comparing with cassete decks. For PCs most known VHS storage systems was ArVid and Danmere Backer.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: February 13, 2023, 11:03:31 am
content: ha ha Tom you explain match exactly how i feelt as a kid going to the scrap for fun goods,some times i was there the whole day with a screwdriver just to open stuff and have a look inside,my local scrap was halve cars halve electronics..

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 13, 2023, 04:48:48 pm
content: The one I referenced was a commercial system, though I don't remember the maker or model. The cassettes had the same physical form as the Phillips audio cassette, but may have had quite different specs on the tape, and the heads on the unit were probably different. I think the capacity per tape was was in the 50-100 Mbyte range so it couldn't have been audio recording. It wasn't fast, I recall between a quarter and half an hour to back up my desktop, which probably had a dozen or two megabytes of data in that era.There where a myriad of tape systems in that era. The HP desktop calculators/computors used a really nifty tape cartridge.

author: rdl
author_rank: Super Contributor
timestamp: February 14, 2023, 02:17:15 am
content: I remember having a couple of those data cassettes when I was in college where we used Commodore PETS. I have no idea what became of them, probably tossed out in a move. The Voyager spacecraft use tape for data storage, some kind of special 8-track machine.

author: IanJ
author_rank: Unknown
timestamp: February 14, 2023, 06:02:07 am
content: Back in the 80's before PC's we used to use Nascom 2 hardware and built our own desktop computers and software which were used offshore and connected to a Drilling Instrumentation system.We used a similar cassette data system that was RS232 driven to save/load data. I remember there were serial commands to read, write, seek etc etc.Can't remember the make, just some big black box with a front loader mechanism.Ian.

author: james_s
author_rank: Super Contributor
timestamp: February 14, 2023, 06:06:16 am
content: Cassette storage was huge during the dawn of the PC revolution, up until the early 80s it was still common and then floppy disk systems dropped in price and took over. The Apple II models up until at least the IIe, the original IBM PC, C64, CoCo, Pet, and most 8 bit home computers had a cassette port.

author: pdenisowski
author_rank: Super Contributor
timestamp: February 14, 2023, 11:04:52 am
content: Quote from: imo on February 12, 2023, 04:21:29 pmI used a cheap cassette recorder as storage for my ZX81 as well. Some people even sold cassette tapes with software "pre-loaded" on them.Biggest issue was storing multiple programs on one cassette tape: needed to use the tape recorder counter number to fast forward to the right point on the tape before using CLOADI still have my ZX81, but finding both an analog television and a cassette recorder might be a little challenging these days ....

author: oz2cpu
author_rank: Frequent Contributor
timestamp: February 14, 2023, 12:35:27 pm
content: funny, my first computer was a ZX-spectrum 48ki never ever used a cassette tape recorder to save / load programs with it,the first thing i did was to see all my friends have a terrible pain with the troubles of adjusting asimutand performing endless retry until it maybe worked or they just gave up..so i got a 3.5" diskdrive and was happy ever after, it only took a few sec to load a program,it was called opus discovery

author: Technical Ted
author_rank: Contributor
timestamp: February 14, 2023, 03:05:08 pm
content: We used a portable unit which was contained in a nice aluminum carrying case to save/load Allen Bradley PLC programs for some of our automatic tube butt welders at Foster Wheeler Energy Corp. That became outdated when PC software was developed and we started using laptops for this function.TedAB2RY

author: iMo
author_rank: Super Contributor
timestamp: February 14, 2023, 03:29:07 pm
content: Quote from: pdenisowski on February 14, 2023, 11:04:52 amThere is a sw (windoze) which emulates the cassette deck via the sound card, you may store/load programs to/from it. I played with it looong time back.. Analog TV is an issue, sure. But all that small home computing stuff from eighties runs on FPGAs today, with the sdcards as the storage medium and at least a VGA..In early/mid 80ties we had a "ZX users club" in our town, people met together on Saturdays and shared/copied their sw. Imagine a room with ~20 users each one with a cassette deck, ZXSpectrum and a TV, loading a game binary from a cassette into the ZX (10minutes+), then running the game to check it out, then copying the binary from ZX to the second cassette (10minutes+), and after that again the step 1 to check it out again. Reliability of the process was not great, you had to mess with the audio levels all the time.. Who copied 3-5 binaries (usually games) during the Saturday's meeting was a lucky guy

author: Kleinstein
author_rank: Super Contributor
timestamp: February 14, 2023, 04:37:39 pm
content: With the C64 I don't remember having problems with the tape laoding. I remember it rather reliable. The original Comodore speed was a bit slow, but there are a short program to speed things up by about a factor of 6. With that higher speed it was pretty fast. The more troublesome point was finding things on a tape. So usually a list of tape counter settings on paper for the directory.The original Comodore tape drive even had a way to stop the motor and a kind of directory program (AFAIR it was somehow combined with the fast loader) could reasobaly well find places on the tape by timing the fast forward time.I faintly remember that on a few occasions they even send computer programs via the TV sound channel.

author: themadhippy
author_rank: Super Contributor
timestamp: February 14, 2023, 05:25:39 pm
content: Quoteor you went round your posh mates house and put his dads twin cassette deck to good use,but dont use high speed copy as it dont work, it was only things like lens lock that spoiled our fun

author: iMo
author_rank: Super Contributor
timestamp: February 14, 2023, 05:34:14 pm
content: They tried to send the sw via public FM radio stations too.. I still remember those experiments well..Also they put plastic gramophone records with the sw recordings (like vinyl singles made of a transparent flexible plastic) inside some computer magazinesThe Commodore drive was a dedicated device, while using common cassette decks the reliability was lower. You had to play with the audio settings, while playing a cassette recording made on a different deck.PS: I wonder whether there was some error correction or data compression, I cannot remember the details.. The data rate was slow, perhaps 50-100bytes per second..PPS: from wiki:Quote

author: james_s
author_rank: Super Contributor
timestamp: February 14, 2023, 05:56:53 pm
content: Quote from: imo on February 14, 2023, 03:29:07 pmI used something like that to bootstrap my Apple IIe which I didn't have any discs for. Actually I think it was just a .wav file I played that booted the machine into a serial transfer program which then allowed me to write a DOS image to a floppy.

author: iMo
author_rank: Super Contributor
timestamp: February 14, 2023, 06:07:23 pm
content: Here is a modern app for the ZX Spectrum cassette deck emulation:https://play.google.com/store/apps/details?id=com.tekdeq.zxtapeplayer&hl=en&gl=USZX Spectrum from vinyl (similar flexible one made of thin plastic with different colors were sold inside some computer magazines in 80ties):

author: themadhippy
author_rank: Super Contributor
timestamp: February 14, 2023, 06:10:46 pm
content: QuoteIn the uk ceefax was also used

author: guenthert
author_rank: Frequent Contributor
timestamp: February 14, 2023, 07:16:04 pm
content: As said before home computers of the early/mid eighties had cassette interface, some had a drive built-in, like the Amstrad (nee Schneider) CPC464. That was just a cheap mass-market tape drive with manual control, better to be forgotten.Some computers, like the Epson HX-20 (first laptop?) had built-in micro-cassette drives, similar to dictation machines. That one was peculiar in that it could control the drive using software, much like large tape drives (nine track, QIC, etc.) in mainframe/mini computers, just much slower and clearly with less capacity. You could write (very slow) DB software using such micro-cassettes. The HX-20 had a 2nd CPU (early MCU), also so that it could reliably keep track of the tape position. Nifty device in '81.