Fantastic job! I’ve been looking at using some old USR modems to build a 70cm point to point simplex radio data link, and this is the perfect starting point.
The youtube recommendation system is creepy. You were talking about this when we were in the You Do It Electronics and today without trying to look you up at all it randomly recommended this video to me. I thought it was some other Jesse with a similar project but I just checked.. I think I might stop carrying my phone with me as often.
So you basically mixed two old technologies. For me more interesting question is what is possible, when there are no limits on coding and decoding algorithms - how much data density and reliability of such storage can be improved?
The modem i used to have used a 240V - 9VAC transformer. I once tried a 9VDC PSU and the modem didn't work properly. It must've been AC because it needed negative voltage. Probably +/- 5V.
@@Mr-Bossman 1,200 baud (in general) should totally be doable on cassette. The modem might be picky, and require better pitch stability than the deck can do though. You could test with a digital recorder to rule out the cassette.
oh thats true. I'm pretty sure its the breadboard though. breadboards are so noisy im genuinely impressed it works at all with how high the noise floor is.
For ATD I play the dial tone over the line then when the pick up is detected i switch to a 2,225Hz tone. For ATA it just expects a 1,270Hz tone which is coming from the cassette player already as its a recording of what the modem sent
It's too complicated. The only thing you need to store data on the tape is your sound card. With simple Manchester encoding (actually BPSK), you can achieve stable 2400 baud, and the implementation is damn simple.
Just curious, what are the uses for this? Is it sort of a gimmick? Like how do you retrieve your files and such? I'm pretty tech illiterate, so I don't have any hope of understanding, I'd still love to get an insight into what you're doing with it though.
I'm try to find a way for very long storage (time capsule) of some images/sound/text and semms that compact cassette + some very well know modulation could do the trick.
@@8001010Linus Tech Tips recently covered a technology that may be of interest to you. Check out their video "The Most Expensive USB Drive on Earth." Don't let the title scare you off. They're basing that claim off of price per GB. The devices currently on the market are very affordable, but they have extremely limited capacity is all, so depending on your requirements it may be a viable option.
as an avid audio cassette enthusiast, this makes me so excited! Heck yeah now I want to do this
Fantastic job! I’ve been looking at using some old USR modems to build a 70cm point to point simplex radio data link, and this is the perfect starting point.
Great Idea! I've been using KCS to send files over radio, I might try to replicate what you have done to make my workflow even faster.
Do note its not actually KCS as the modem uses a slightly different encoding. I found that out after naming it because I'm dumb
This is cursed and I love it
I'm surprised it was possible to trick device, which is designed for 2-way communications, to accept 1-way "broadcast".
that's probably what the mcu is doing, setting up a handshake for a given speed (good enough for a tape) and letting the tape record or play
Wow, tape-counter! Makes me wanna dig up my old cassette player.
Makes me think about Basicode (sends basic programs over FM ).
An Impressive Hack! - Nice Job! - Gives ideas for doing similar fun!
The youtube recommendation system is creepy. You were talking about this when we were in the You Do It Electronics and today without trying to look you up at all it randomly recommended this video to me. I thought it was some other Jesse with a similar project but I just checked.. I think I might stop carrying my phone with me as often.
That's actually crazy
@@Mr-Bossman Google is creeping me out.
its been happening for years, since 2017 officially when google addmitted they do this in their tos 😊
I guess it is most basic 300 baud speed for audio coupled modems?
It looked like it took a bit over 30 seconds for his 1158 byte file, so that's about 300 baud, yeah? Super cool experiment!
yes 300 baud
So you basically mixed two old technologies.
For me more interesting question is what is possible, when there are no limits on coding and decoding algorithms - how much data density and reliability of such storage can be improved?
Could you update the github link in your video description? It’s been truncated and doesn’t work.
These modems used an AC to AC adapter which is weird since most devices use AC to DC.
It was quite common to have AC to AC adaptors in the past.
Do you know what's the benefits of an AC to AC adapter, does it isolate the system better or maybe the cmos technology etc needed negative voltage.
The modem i used to have used a 240V - 9VAC transformer. I once tried a 9VDC PSU and the modem didn't work properly. It must've been AC because it needed negative voltage. Probably +/- 5V.
This is one of the slower FSK modes, right? Have you tried the faster PSK ones?
the 1,200 baud FSK didn't work and negotiation to higher speeds i haven't figured out yet.
@@Mr-Bossman 1,200 baud (in general) should totally be doable on cassette. The modem might be picky, and require better pitch stability than the deck can do though. You could test with a digital recorder to rule out the cassette.
oh thats true. I'm pretty sure its the breadboard though. breadboards are so noisy im genuinely impressed it works at all with how high the noise floor is.
@@Mr-Bossman I'd guess the biggest source of noise is the cassette. You can bandpass it just around the two FSK tones to cut some noise.
Now you just need a circuit to write the file to zx-spectrum memory then you could have a tape loader that loads in record times!
Hey I was using Kansas city standard before. Is this faster or does it have the same rate?
I think its possible to get it to go faster but as of now its stuck at 300 baud
How you trick modem in "connected" mode?
depends on the modem i guess. need to check the manual. "some" you can setup into "lease line" (always connected) mode , for example.
For ATD I play the dial tone over the line then when the pick up is detected i switch to a 2,225Hz tone. For ATA it just expects a 1,270Hz tone which is coming from the cassette player already as its a recording of what the modem sent
cool a wiring diagram of the bread board would be nice!
Link in the description, instead of "KC..." put KCS_modem
It's in the description github.com/Mr-Bossman/KCS_modem
That's cool. Sounds like a very slow data rate, though? Like 300 baud? You should be able to get 1200 baud going easily.
Interesting but why?
That’s neat!!! ❤
Nice. What speed do you use for the modem? I'm used to it reporting connection speed when printing "Connected" but not here apparently.
300 baud. yes it is weird it doesn't say the speed
It's too complicated. The only thing you need to store data on the tape is your sound card. With simple Manchester encoding (actually BPSK), you can achieve stable 2400 baud, and the implementation is damn simple.
yes, I do know. It is way cooler to use a modem to do it though
Just curious, what are the uses for this? Is it sort of a gimmick? Like how do you retrieve your files and such? I'm pretty tech illiterate, so I don't have any hope of understanding, I'd still love to get an insight into what you're doing with it though.
playing is learning. and learning is always a good investment.
I'm try to find a way for very long storage (time capsule) of some images/sound/text and semms that compact cassette + some very well know modulation could do the trick.
@@8001010Linus Tech Tips recently covered a technology that may be of interest to you. Check out their video "The Most Expensive USB Drive on Earth." Don't let the title scare you off. They're basing that claim off of price per GB. The devices currently on the market are very affordable, but they have extremely limited capacity is all, so depending on your requirements it may be a viable option.
its a technically interesting exercise that is just for fun and novelty, stuff like this is very satisfying to our autistic brains lol
@@Re_Kitty love that! Not everything needs to have real world applications, sometimes we just wanna see what we can do
Link on github is broken(
Instead of "KC..." put KCS_modem
should be fixed now
@@Mr-Bossmanyes. Thank you!
Oh great, you just discovered what EVERY COMPUTER DID in the 70s and 80s...