An Atari Tape Interface

[charliecron]

Here is an article from the January 1984 issue of "Computers & Electronics" magazine. It's a tape interface circuit so you can use any tape player/recorder.

 

I have not seen this anywhere so figured I would scan and post it.

 

We get a lot of 'My tape drive don't work' posts every now and then, maybe some folks would like to build their own interface.

 

The full article is a zipped PDF.

 

Charlie

[Bryan]

Neat. I remember seeing a similar DIY project somewhere too.

 

I imagine this interface won't load if the tape has an audio track unless it was used with a stereo player.

[Fox-1 / mnx]

This one is about the same but supports up to 5000 baud and is intended to connect a CD player but any audio source will do:

 

http://sites.google.com/site/ataripal/megacd

 

 

 

[carmel_andrews]

I bought a GE or was it a GEC tape interface (it was a combo c64/atari type) unfortunately i broke it

[Chilly Willy]

This one is about the same but supports up to 5000 baud and is intended to connect a CD player but any audio source will do:

 

http://sites.google.com/site/ataripal/megacd

 

 

 

 

Nice, but don't forget to run the other audio input to pin 11 of the SIO... that's how you get the cassette audio on the Atari sound for educational cassettes. One side has the data, and the other side has the audio.

[charliecron]

 

Nice, but don't forget to run the other audio input to pin 11 of the SIO... that's how you get the cassette audio on the Atari sound for educational cassettes. One side has the data, and the other side has the audio.

 

I was wondering about that, the schematic I posted has a connection to "J1-11" I imagine that should read "P1-11"?

[Chilly Willy]

 

Nice, but don't forget to run the other audio input to pin 11 of the SIO... that's how you get the cassette audio on the Atari sound for educational cassettes. One side has the data, and the other side has the audio.

 

I was wondering about that, the schematic I posted has a connection to "J1-11" I imagine that should read "P1-11"?

 

Probably, plus it shows only a mono plug for the sound in which should be stereo with one side going to the chip and the other going to P1-11.

 

It's not too surprising the CD interface doesn't connect them - it uses a higher frequency for the FSK for faster throughput, so it's geared towards just data, not data + sound. Connecting the audio in to the Atari is mainly for direct replacements of the cassette. I do find the idea of using a CD as a cassette replacement rather intriguing. What is needed is for someone to publish a mod for connecting the motor line from the SIO to a portable CD player pause control so that the CD acts exactly like the cassette. Or maybe a mini MP3 player.

Edited January 19, 2011 by Chilly Willy

[Rybags]

I think we went through something similar before - the more logical use for CD player would be to just have the CD directly driving the SIO Input line.

 

Forget this FSK decode crap - you could in theory have a cassette boot a couple of blocks at a normalish 750 bps or so, then have the remaining portion of the program load in one big block at 22,050 bps or so.

Would likely need some electronics on the CD player side to normalize the signal to keep SIO happy, but I don't see any reason why even 44,100 bps couldn't work, other than the audio circuitry in the CD player doing undesirable stuff to the signal.

[Kr0tki]

but I don't see any reason why even 44,100 bps couldn't work,

AFAIK the Czech/Slovakian guys have done exactly that - an interface for loading from CD with 44100 baud.

[charliecron]

I bought a GE or was it a GEC tape interface (it was a combo c64/atari type) unfortunately i broke it

 

Yes I have one of these, though it did not come with the cable. I may try and make my own cable actually, can't be that hard.

 

There are nice pictures of it in this thread,

 

http://www.atariage.com/forums/topic/161936-atari-1010-problem/

 

He mentions this interface can be used with any tape player, though the box warns to only use the included recorder. I do believe there is a switch on the recorder itself to switch between Atari/Commodore, but could be on the FSK interface, pretty sure it's the recorder though. GE still makes a nice recorder in the same style by the way..just saw one in WalMart.

[Fox-1 / mnx]

Nice, but don't forget to run the other audio input to pin 11 of the SIO... that's how you get the cassette audio on the Atari sound for educational cassettes. One side has the data, and the other side has the audio.

 

The reason the interface is using only 1 channel (not mono) is that you can use both audio channels to store data, so 1 audio track can have a game on the left channel and a different one on the right channel.

 

Of course one can wire it the way he wants to.

 

But there are other ways to load tapes.

 

Once, I modded a 1010 to use external audio input/output. The output was wired to an FM transmitter, the input to an FM radio receiver. A friend, 10 KM's away, has the same set-up and while using a stereo FM set-up we could talk on one audio channel when using the other channel to exchange data. As long as the volume was kept low it worked.

 

The most easy way to use an alternative audio source is by getting one of these:

http://en.wikipedia.org/wiki/Cassette_tape_adaptor

 

 

Put it in an Atari tape recorder and just connect the wire to another, better, audio source.

 

I tried one years ago and it works. Don't expect HQ quality audio but it's good enough for data.

 

 

edit: typos'

Edited January 20, 2011 by Fox-1 / mnx

[charliecron]

Yes those are cool, I keep one handy. Good for folks with bad belts in their deck. These are pretty cool too, they will actually take an SD card and you can pop it in your deck!

[Chilly Willy]

Those are both really good ideas. I've got one of those fake cassette with line in, but never thought to use it for the Atari. I actually got it for my PSP to use in the RV on long trips.

[Bunsen]

I bought a GE or was it a GEC tape interface (it was a combo c64/atari type) unfortunately i broke it

 

I've got the same, but haven't got it to work. Do you have a manual or software for it? Maybe mine is broken, too?