Cassette input/output to PC's mic & headphones

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I was trying to record data from my Apple IIe on a PC, by connecting the Apple's cassette in/out to the PC's mic input and headphones output. Mostly because I wantet to save some stuff, and I had no tape recorder. But I could never do a proper recording/playback of the data. The PC did record some noisy modem-like audio, which sounded OK, but the Apple never managed to read back the data properly (I think it failed a few times with a checksum error, and a few times without error).

Any suggestions? Shouldn't it be possible to do this?

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Joined: Apr 11 2006
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It's all about the audio level

Seems like it ought to work. The "modem-like audio" is definitely the sound of the Apple's output. You'd have to make sure that the record and playback levels were equivalent - both of which are independently modifiable on your PC. I don't know what (if any) amplification the mic input adds; the headphone jack is of course completely variable. Can the Apple hear back what it said at about the same volume?

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I would suggest using your PC

I would suggest using your PC's line in jack rather than the mic input.

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That is a good idea, but ther

That is a good idea, but there is no line in on my PC (a laptop).

DrBunsen's picture
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Open the saved audio file in

Open the saved audio file in any sound editing app that has a waveform view.

If the waves are taking up the whole vertical height of the wave display (there should be a light or dotted line to show you the upper and lower limit) then they are clipping and overloading the input. Either the output is too high, or the input on the laptop is applying amplification and is too high. Find the input gain control for your operating system, turn it down and try again.

If the waves are hardly taking up any of the vertical height, they are probably too quiet for the Apple to hear back properly. Turn your input gain up and try recording again - or use the existing recordings and turn your output volume up.

If the waves look fine (ie about 3/4 of the available height and no clipped waves at the top/bottom where they hit the limit and go horizontal for a bit) then it's probably the playback volume being either too high or too low. Fiddle with that.

Good luck. I know this can be done because I use a DAT (digital audio tape) to save programs from my Roland Tr-707 drum machine's "Tape Save" output.

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If you've got some kind of on

If you've got some kind of onscreen meter where you can monitor the input and output levels on the fly, and adjust them, that'll help a lot.

BTW I remember there's a cool little app that does this for a Roland MC-202 sequencer - but it also converts to/from standard MIDI files Smile ie it can take the raw tape save soundfile and turn it into a MIDI version of the sequence data, and vice versa. Wouldn't it be cool if someone coded up an Apple version, ie write in BASIC or machine code on your PC then convert it to a sound file.

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related subject- Apple 1 cassette interface

Check out the Apple 1 forum. Vince has been working on a cassette interface for the Apple 1/Replica 1 and has had similar issues.

http://www.applefritter.com/node/19984

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RE: Cassette input/output to PC's mic & headphones

I want to transfer Apple IIe *.dsk files through my sound card to the Apple IIe tape recorder jacks, is it possible? I know the file has to be converted to wav, but how?

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ADTPro has that capability.

ADTPro has that capability. You don't have to convert it to .wav; it gets converted and sent on the fly.

http://adtpro.sourceforge.net

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O k I downloaded the program

O k I downloaded the program is there a tutorial? After I send a file over it doesn't come back to the prompt on the IIe. and that's just sending the bootstrap files.

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Re: O k I downloaded the program

jescis wrote:

is there a tutorial?

Just so happens, there is. See here:
http://adtpro.sourceforge.net/bootstrapaudio.html

jescis wrote:

After I send a file over it doesn't come back to the prompt on the IIe. and that's just sending the bootstrap files.

That might be because the Apple IIe isn't "hearing" what your big computer is "saying". Make sure 1) the connections are correct (See:
http://adtpro.sourceforge.net/connectionsaudio.html
and 2) make sure the volume is turned WAY up.

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Re: Re: O k I downloaded the program

thanks, EsDOS is now loaded Laughing out loud
though I don't have the 5.25 floppy drive(s) or the hardware to use them.

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Of chickens and eggs

Ok, you've gotten that far. That's a good thing. If you have no serial card, and if you have no ProDOS diskette anywhere in your collection - you will eventually run into the problem of getting ADTPro running under ProDOS on your IIe. The problem is that there isn't a way to bootstrap the ProDOS operating system over the cassette ports (yet). So you can't get all the way from bare metal to ProDOS over the cassete ports alone.

Let us know what your situation is. (Do you have a ProDOS diskette anywhere?) If all else fails, you can send me a SASE with a floppy diskette and I'll format it and put ADTPro on it for you so that you can get going.

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Re: Of chickens and eggs

I got my Apple IIe off of eBay with nothing but the main unit without any add ons or monitor. I'm using it with a HD 37" television using a composite cable. also the only disk I ever had had my school stuff on it.

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No floppies?

Ok, if you have no floppy drives - then you need to head back to eBay and get one. Or, get a super serial card and play with the Apple Game Server: http://a2gameserver.berlios.de/. But you aren't going to get very far trying to read an Apple floppy disk with PC hardware.

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RE: No floppies?

I'm getting a "New Slim 5.25" DISK DRIVE" and a "New 5.25" DRIVE CONTROLLER (For II+/IIe)" from MC Price Breakers. Laughing out loud

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One other point to make

Take care about this:

The audio adjustment comments are great.

I already figured out that the no-disk drive issue is the show-stopper here in this thread.

But I have one other recommendation that wasn't brought up:
DO NOT USE COMPRESSED AUDIO on the Windows side!
I have some experience on this with some other stuff I've been into, an emulator I wrote for the old RCA COSMAC prompted me to convert some old tapes to CD, and also some TRS-80 work I've done.

The Apple II cassette interface uses more bandwidth than either of the two above that I've mentioned.

Trust me: if anyone here is considering an archive of audio-format data (such as tapes), make sure to record using NO compression, and save the files in an uncompressed format!

For my RCA tape-to-CD project I used AudioGrabber (which is usually used for CD ripping), and the (Windows .WAV) files I wound up generating were amusingly enormous, but the RCA can read the files as stored in the CD's audio format with no problem. PCM or MP3 or OGG compression of the audio resulted in the RCA TINY BASIC replying "WHAT?" (meaning data error).

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Re: One other point to make

CaveNerd wrote:

For my RCA tape-to-CD project I used AudioGrabber (which is usually used for CD ripping), and the (Windows .WAV) files I wound up generating were amusingly enormous, but the RCA can read the files as stored in the CD's audio format with no problem. PCM or MP3 or OGG compression of the audio resulted in the RCA TINY BASIC replying "WHAT?" (meaning data error).

Good point. MP3, etc. compression strips out lots of the timing-critical wave transitions that the Apple listens for. Compression is definitely not the answer. Sample rates need to be reasonably high, too. In my audio code, I use 44.1kHz to get the best fidelity. I can get away with that because I never store the data anywhere in that form - the data just passes through the buffer on its way to/from the sound card. I experimented with lower frequencies, but eventually started losing data. Capturing data back, for example, started losing resolution fast with anything less frequent than 22kHz.

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I've done this successfully u

I've done this successfully using a Sony portable DAT to save and re-load program data to and from a Roland TR-707 drum machine. The idea of burning the saves off to CD never occurred to me, but it makes perfect sense.

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Burning software as audio to CD is funny

It's actually a nice way using modern tech to preserve data saved as audio. It's also quite amusing, since the size of the audio file using an optimal 44kHz, 8-bit mono (uncompressed) format will result in a file several dozen times the size of the data being preserved!
One nice thing about it though is saved as separate audio tracks, a cassette that had several files on it is now random accessible. No more tedious, nerve-scraping scans of a tape to find a program somewhere in the middle.
Another nice thing about this is damaged cassettes can be easily repaired (as long as the data wasn't totally lost) - digitized as a modern sound file, using whatever your favorite (uncompressed) format is and your favorite sound editing tool - you can repair minor dropouts by increasing volume and scrubbing the signal/noise (gently, carefully - and TEST IT!)

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I guess you could use each ch

I guess you could use each channel of a stereo CD for twice the storage, and an appropriate left/right splitter cable to reload.

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ProDOS over the cassette ports

david__schmidt wrote:

The problem is that there isn't a way to bootstrap the ProDOS operating system over the cassette ports (yet).

For the record - the ADTPro project can now boot a diskless Apple II all the way to ProDOS over the cassette ports. See:
http://adtpro.sourceforge.net/bootstrapaudio.html