Using a FSK modem as tape storage interface

[ChristofferB]

So once again, I'm back with something completely obsolete, but kinda interesting anyway.
I was reading up on a FSK-modem on-a-chip (AM7910PC), and it really looks very simple to use. So would it be possible to connect the RX/TX line directly to speaker/mic lines on a cassette/reel tape deck, and store serial data that way?
Could you use a old junk modem for this purpose? has it been done?

-No, I understand this isn't a very efficient solution, but it's intriguing, isn't it??

--Christoffer 

[nctnico]

This exactly how old home computers like Commodore 64, MSX, etc saved data onto audio tapes! This technology is from the beginning of computing.

[ChristofferB]

Exactly! Now, since modem hardware uses the same-ish FSK ideas; could you use modem hardware for the same purpose?

--Christoffer

[NiHaoMike]

You'll have to emulate the handshake signals, but it is possible.

For a bit more fun on something just slightly more practical, figure out how to read and write digital data on VHS tapes. Hint: SDR would probably be the easiest way to do it.

[ChristofferB]

Yeah, I was hoping to use /DTR and /RTS to make a send/receive switch.

--Perhaps. A VHS tape can have up to 20 GB of storage space. Might be interesting.

-Christoffer

[timb]

You'll have to emulate the handshake signals, but it is possible.

For a bit more fun on something just slightly more practical, figure out how to read and write digital data on VHS tapes. Hint: SDR would probably be the easiest way to do it.

Back in the early 2000's, when digital camcorders had FireWire ports, I used my camcorder and MiniDV cassettes for backups. There was some software that would record the data across FireWire to the tape. If you played the tape back on a TV, you would see snow and lines, which was the actual binary data.

It was a super cheap way to get 20GB of backup space. I rotated tape sets and kept them offsite. Worked really well!

This is nothing new, though. I know as early as 1971 they were storing digital data on U-matic cassettes.


Sent from my Tablet

[German_EE]

Way back in the early 1980's I was one of the many who saved their precious data on cassette tapes, in my case it was a TRS-80 Model 1. Yes, you could use an FSK modem as a tape interface but some things just deserve to die.

[matseng]

--Perhaps. A VHS tape can have up to 20 GB of storage space. Might be interesting.
-Christoffer

The Russians used to store up to 2 GB on a VHS tape about 20 years ago.  https://en.wikipedia.org/wiki/ArVid

[ChristofferB]

Way back in the early 1980's I was one of the many who saved their precious data on cassette tapes, in my case it was a TRS-80 Model 1. Yes, you could use an FSK modem as a tape interface but some things just deserve to die.

A lot of innovations that deserve to die doesn't, like what I just suggested, and a lot of innovations that deserve to live dies, like the punched tape, and diode matrix roms..

If nothing else, it'll be interesting. And when you have a computer that ONLY talks serial, it might not be too stupid a solution