Does anyone here have a cassette recorder? I want to ask a favor of you.
I've written a program that converts data to an audio signal, and converts the audio signal back to data.
I currently have it working reliably with two different cassette recorders that I own, but I want to know if it works with other cassette recorders as well (since every recorder differentiates the signal in a different way).
I'll post a flac recording of the signal, and if you have a tape recorder, please record the signal on a tape, and link to a flac recording of the output from your cassette recorder.
I have a recorder but I'll be near in an hour. How about you tell about your technical sides of the program?
Jackson Miller
Nice ear rape. So is this just sstv but with anything instead of just images?
Landon Rivera
I wrote it in BBC Basic. It stores a binary '0' as a high amplitude wave and a binary '1' as a low amplitude wave.
I dunno anything about sstv, but yeah, it can take any kind of data.
Dylan Jones
I have troubles understanding what's so special about a 2 bit PWM triangle shaped signal with 3.14 kHz of base frequency and what's a tape recorder got to do with but the DAC of my soundcard
Jeremiah Edwards
I have over 50 recorders and 20 tape decks (collection). Want me to test it on a few for you.
Nathan Fisher
Yeah, if you don't mind trying it out. Record it on a tape, then record it into your comptuer from the tape using the same tape machine you recorded it with.
Brandon Hernandez
okay.
Kevin Cook
I think OP assumes (some) tape recorders distort the audio. And he's probably right.
Anyways, storing data on cassette tapes used to be very common. I'm sure there's still plenty of documentation about it available.
Christopher Nelson
this seems really interesting even if I don't understand what's going on
Grayson Bailey
>probably there's no doubt both the recording operation and the nature of the tape media will distort the sound. it'll just add some arbitrary phase shift, cut the frequency components higher than 8 kHz at some filtering order and add a little bit of brown noise. nothing you can keep track of with a 2 bit input signal imo.
Colton Ramirez
Yeah, in my tests with the two different tape recorders I own, the signal looks different depending in which tape player I used.
holy shit... the signal is totally distorted beyond all recognition. Maybe you had the input volume into the tape recorder set too high. Thanks anyway.
Jose Garcia
Nope, thats just how shitty the recorder is.
Eli Peterson
Can you post the code?
Owen Brown
Let me just say the default tape loading system used by the ORIC-1 sucked donkey balls and closely resembles what you're using...
The BBC Micro used a better trick. (I mean, if you're writing it in BBC Basic you may as well just *SAVE to use it yourself! You'd want to use 6502 assembly language to process the raw signal fast enough.)
Yes, tape distorts the audio more than you might even want to believe. Think of it as bandpass 500Hz-2500Hz on a good day, with wow, flutter, phase all over the place, random volume fluctuations, god, everything. You're going to want to get the screwdriver and adjust the phase to get some 3000Hz+ frequencies back at least.
A lot of docs got thrown away. I know mine did from when my brother wrote his own tape loading system (with built-in XOR scrambling!). Common copy-protection thing, but block markers and checksums were luxuries that it was worthwhile to add too, so you could rewind and try again on errors... I even saw one with parity once.
Adrian White
uhmmm, whats so special about this? are you trying to recreate a c64 datasette or something? or are you trying to improve the amount of data you can store on a normal tape?
Sebastian Jenkins
Holy crap, someone else has that cassette recorder!
Mine's broken right now, but still. (Turns out putting it in your pocket with headphones inserted is an awful idea. Gotta get out the soldering iron. Blegh.)
Also, yeah, it's kinda crap. Speed is a bit all over the place. But it's nice for listening to music, anyways. Never tried recording.
Cameron Rivera
Do you have any ORIC-1 recordings or know where I could find some? I'd really like to see what the signals look like.
just for fun project
Logan Fisher
Hey, that's pretty cool.
Mine had speed issues so I had to buy and replace the rubber belt on the inside. Works fine now except it records and plays terribly.