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Recordings of cassette loader music?

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Does anyone have recordings of the loader music from cassette games? They were recorded on one of the analogue channels on the tape.

I recall some quite interesting tunes from the loaders for synapse games...

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no? :sad:

 

I don't remember music on the analogue side of the tape for any games. The only program I remember this for was Introduction to Programming. I do remember a game though (Ghost Hunter or similar) that actually used to play music from Pokey while it loaded the rest of the game.

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IIRC a number of early Atari titles had an audio track whilst loading. Kingdom certainly did and the European version of States and Captitals (Countries and Capitals) did too. They consisted of some great cheesy music and a male voice talking about the game being loaded. Actually I used to quite enjoy listening to the Kingdom one.

 

Obviously the Conversational languages (Spanish, French, German etc) used the audio track on the cassette too.

Edited by spookt

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Wow! I had no idea there were such tapes but that's no wonder, we had no chance to buy any original tapes during the so called socialism in the former Czechoslovakia. The pirates didn't bother. :)

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Yeah, this was a cool feature. I've never seen Ape or any of the emulators can simulate audio from the tape. You just have to buy a tape drive and play these with real hardware.

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i recall most of the synapse games had loader music. zeppelin had some quite nice tracks for instance.

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Yeah, this was a cool feature. I've never seen Ape or any of the emulators can simulate audio from the tape. You just have to buy a tape drive and play these with real hardware.

 

You should be able to simulate the Atari cassette recorder's both tracks (audio and digital data) with a CD-player by recording the audio on one of the channels (say left channel) and the digital data on the other channel (say right channel). Then you just need to feed the audio out left channel into the SIO audio in line and the audio out right channel needs to be converted (and amplified) from 0.. 1Vpp to 0..5V DC and fed into the SIO Data In line. You could record the CD in such a way so that the audio playback rate (150kb/second) produces a 600bps equivalent data output in the conversion circuit for the data and audio normally (on the left channel). Then you could use the MOTOR control line to set CD to start playing current track and DATA OUT line to seek next track in a loop through all tracks on the CD. Some programs may need to be modified to use MOTOR/DATA OUT properly. For new custom programs, they can use the SYNC marks put on the CD (via location 53775) and take advantage of the CD features for audio w/o loading any programs from it. The hardware should work with any CD player with stereo audio outputs.

 

I guess if you play the mono CDs on a stereo speaker system, the right channel would just cause some clicks at end of audio tracks or phrases.

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Yeah, this was a cool feature. I've never seen Ape or any of the emulators can simulate audio from the tape. You just have to buy a tape drive and play these with real hardware.

 

You should be able to simulate the Atari cassette recorder's both tracks (audio and digital data) with a CD-player by recording the audio on one of the channels (say left channel) and the digital data on the other channel (say right channel). Then you just need to feed the audio out left channel into the SIO audio in line and the audio out right channel needs to be converted (and amplified) from 0.. 1Vpp to 0..5V DC and fed into the SIO Data In line. You could record the CD in such a way so that the audio playback rate (150kb/second) produces a 600bps equivalent data output in the conversion circuit for the data and audio normally (on the left channel). Then you could use the MOTOR control line to set CD to start playing current track and DATA OUT line to seek next track in a loop through all tracks on the CD. Some programs may need to be modified to use MOTOR/DATA OUT properly. For new custom programs, they can use the SYNC marks put on the CD (via location 53775) and take advantage of the CD features for audio w/o loading any programs from it. The hardware should work with any CD player with stereo audio outputs.

 

I guess if you play the mono CDs on a stereo speaker system, the right channel would just cause some clicks at end of audio tracks or phrases.

 

Regarding the 150KB/second data rate, the audio sampling rate to be converted would be 44.1Khz.

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The Atari tape deck demodulates the two-tone signal into 0/1 bits.

 

Unsure if you could have a CD doing that... maybe a case of having lots of successive sample values of 0 or 32767 to represent each bit.

 

But, it would be a pretty wasteful way of storing data.

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The Atari tape deck demodulates the two-tone signal into 0/1 bits.

 

Unsure if you could have a CD doing that... maybe a case of having lots of successive sample values of 0 or 32767 to represent each bit.

 

But, it would be a pretty wasteful way of storing data.

 

We do not need to store the two-tone signal nor demodulate the 5327Hz/3995Hz signals. We just need to convert the audio output of one of the channels into 0..5V signal for the Data In line so the Atari thinks a cassette player is hooked up to it but it's actually a CD. Note that the Atari receives digital data on the Data In line not the two-tone signal.

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Yeah, this was a cool feature. I've never seen Ape or any of the emulators can simulate audio from the tape. You just have to buy a tape drive and play these with real hardware.

 

You should be able to simulate the Atari cassette recorder's both tracks (audio and digital data) with a CD-player by recording the audio on one of the channels (say left channel) and the digital data on the other channel (say right channel). Then you just need to feed the audio out left channel into the SIO audio in line and the audio out right channel needs to be converted (and amplified) from 0.. 1Vpp to 0..5V DC and fed into the SIO Data In line. You could record the CD in such a way so that the audio playback rate (150kb/second) produces a 600bps equivalent data output in the conversion circuit for the data and audio normally (on the left channel). Then you could use the MOTOR control line to set CD to start playing current track and DATA OUT line to seek next track in a loop through all tracks on the CD. Some programs may need to be modified to use MOTOR/DATA OUT properly. For new custom programs, they can use the SYNC marks put on the CD (via location 53775) and take advantage of the CD features for audio w/o loading any programs from it. The hardware should work with any CD player with stereo audio outputs.

 

I guess if you play the mono CDs on a stereo speaker system, the right channel would just cause some clicks at end of audio tracks or phrases.

 

 

Yeah, this would be a fun little project. I suppose it's also be possible to play wave files off of an SD card or something like this, but I kind of see the retro-factor in having a physical CD version of some of those old Atari tapes. It provides a straightforwards way to backup -- audio to audio.

 

Me, I never actually owned any of the educational System tapes. I assume when they reach the end, they prompt you to rewind? I guess there's no way to detect this, and the player just has to push a button to restart the thing. Or when the Atari goes 'Bleep, bleep -- motor on' then it knows to rewind? And just 'motor on' means continue on the current tape?

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The Atari tape deck demodulates the two-tone signal into 0/1 bits.

 

Unsure if you could have a CD doing that... maybe a case of having lots of successive sample values of 0 or 32767 to represent each bit.

 

But, it would be a pretty wasteful way of storing data.

 

all i care about is the music on the tapes :cool:

 

the games were available in disk or cartridge versions.

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Yeah, this was a cool feature. I've never seen Ape or any of the emulators can simulate audio from the tape. You just have to buy a tape drive and play these with real hardware.

 

You should be able to simulate the Atari cassette recorder's both tracks (audio and digital data) with a CD-player by recording the audio on one of the channels (say left channel) and the digital data on the other channel (say right channel). Then you just need to feed the audio out left channel into the SIO audio in line and the audio out right channel needs to be converted (and amplified) from 0.. 1Vpp to 0..5V DC and fed into the SIO Data In line. You could record the CD in such a way so that the audio playback rate (150kb/second) produces a 600bps equivalent data output in the conversion circuit for the data and audio normally (on the left channel). Then you could use the MOTOR control line to set CD to start playing current track and DATA OUT line to seek next track in a loop through all tracks on the CD. Some programs may need to be modified to use MOTOR/DATA OUT properly. For new custom programs, they can use the SYNC marks put on the CD (via location 53775) and take advantage of the CD features for audio w/o loading any programs from it. The hardware should work with any CD player with stereo audio outputs.

 

I guess if you play the mono CDs on a stereo speaker system, the right channel would just cause some clicks at end of audio tracks or phrases.

 

 

Yeah, this would be a fun little project. I suppose it's also be possible to play wave files off of an SD card or something like this, but I kind of see the retro-factor in having a physical CD version of some of those old Atari tapes. It provides a straightforwards way to backup -- audio to audio.

 

Me, I never actually owned any of the educational System tapes. I assume when they reach the end, they prompt you to rewind? I guess there's no way to detect this, and the player just has to push a button to restart the thing. Or when the Atari goes 'Bleep, bleep -- motor on' then it knows to rewind? And just 'motor on' means continue on the current tape?

 

A simple implementation of the simulation algorithm would be to let user select the track which contains the game+audio on the two tracks. User boots up Atari with START button (assuming binary file like Space Invaders here). Atari will play the custom tune in the left channel of the CD while loading the data for the game simultaneously. After music stops playing, Space Invaders will start as if loaded from cassette. This is do-able without using the motor line or data out line-- simply using Audio In (from left channel of cd audio out) and Data In (from right channel of cd audio out). Atari OS will adapt up to 880bps easily so we can fit 488,400 bytes of data on one 74 minute audio CD along with 74 minutes of audio and the CD will boot on any Atari 8-bit computer w/o any drivers.

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We already discussed this - starting around here: http://www.atariage.com/forums/index.php?s...t&p=1481552

 

One big problem with this is that if you try to run the bitrate that low, the internal filter on your CD player is likely to strip out the waveforms (plus do other crap to your signal). So you can't just directly translate the 1s and 0s to +0/+5. There are a few solutions: one is to record Atari tapes to CD, use one of those CD-to-Tape adapters, and put the tape adapter in a 410.

 

Or strip out the FSK decoder of the 410 and put it inside a project case or the CD player itself. Or, come up with a different kind of encoding scheme and build a new decoder for the CD. Since the cassette loader is way slower than the SIO ports, maybe it would be a better solution to make a new audio->SIO decoder and have the CD drive appear as a read-only 810?

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We already discussed this - starting around here: http://www.atariage.com/forums/index.php?s...t&p=1481552

 

One big problem with this is that if you try to run the bitrate that low, the internal filter on your CD player is likely to strip out the waveforms (plus do other crap to your signal). So you can't just directly translate the 1s and 0s to +0/+5. There are a few solutions: one is to record Atari tapes to CD, use one of those CD-to-Tape adapters, and put the tape adapter in a 410.

 

Or strip out the FSK decoder of the 410 and put it inside a project case or the CD player itself. Or, come up with a different kind of encoding scheme and build a new decoder for the CD. Since the cassette loader is way slower than the SIO ports, maybe it would be a better solution to make a new audio->SIO decoder and have the CD drive appear as a read-only 810?

 

I just read that thread you mentioned and I don't see any verifiable conclusion regarding why you would need a FSK decoder for a CD. Your speculation that the CD player will "strip out" the waveforms if we simulate low bitrates does not follow from that thread nor this one. Unless you can give evidence for this, isn't it better to try it out rather than imagine it can't be done. I can make a rational argument that it should not be stripping out the waveforms. And I never stated anything about 1s and 0s translating to +0/+5V so this topic has not been discussed there at least from the perspective I see it. You have 44100Hz waveforms going through a 16bit DAC so you are dealing with -32768..32767 values and you don't have to use a fixed value for "1" and if your CD player is going to strip out a range of values say from 32000...32767, it's not really a 16-bit DAC. 44100Hz can be broken down into 7*7*5*5*3*3*2*2Hz so taking a ratio of 50:1 gives you 882bps rate. You are talking around a millisecond when the sample level will be about the same. Even if there is clipping, you should wind up with the 0/5v output.

 

Regarding the slow SIO port, you don't have to stick to 882bps once the boot sector is loaded. After the boot block, you can reprogram the SIO to run at the full throttle 44100 bps. No, 810 disk drive would be harder than using cassette because 19200 baud does not divide evenly into the 44100. And the point was to have the audio playing atleast alongside, so we want to stick to the 882bps or lower otherwise Space Invaders or other application will load up in a few seconds defeating the purpose of cassette simulation.

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The Atari tape deck demodulates the two-tone signal into 0/1 bits.

 

Unsure if you could have a CD doing that... maybe a case of having lots of successive sample values of 0 or 32767 to represent each bit.

 

But, it would be a pretty wasteful way of storing data.

 

all i care about is the music on the tapes :cool:

 

the games were available in disk or cartridge versions.

 

Since you care about the music, I suppose you can make it so that if someone inserted a CD in there that did not have the program encoded into the right channel, you'll get a chksum error and you can play the right channel through the 53279 register using a 1-bit DAC and put up an error message like "I hear music on this channel rather than see Space Invaders program."

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I think it sounds feasible... but aren't Line Levels normally somewhere in the 1 Volt area?

Also, AFAIK most CD players have oversampling, where the hardware generates interpolated values between real samples to smooth out the waveform.

 

I've just generated a raw file and converted to WAV. Just half a second of 55 zeros/55 ones repeating.

I'll play it through my set-top DVD player which is connected to the PC and see what we get back.

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Here's the post I made to a DSP users group a few months ago.

 

http://www.dsprelated.com/showmessage/93148/1.php

 

> Why do you even need to encode the ones and zeros? Couldn't you just

> write the 600 baud, unencoded stream to the CD (I assume around

> 44,100/600 samples per baud)?

 

The audio bandpass filter on typical CD players output won't

pass your data undistorted if the local frequency is too low.

e.g. if any region of data containing long strings of ones or

zeros looks like something below about 20 Hz. You also have

the problem of recovering the bit clock, although that's a

bit less of a problem with a CD than with an old audio tape

drive.

 

EDIT: So maybe it could work if you never had a sequence of ~30 1s or 0s in a row...?

Edited by Hornpipe2

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I think it sounds feasible... but aren't Line Levels normally somewhere in the 1 Volt area?

Also, AFAIK most CD players have oversampling, where the hardware generates interpolated values between real samples to smooth out the waveform.

 

I've just generated a raw file and converted to WAV. Just half a second of 55 zeros/55 ones repeating.

I'll play it through my set-top DVD player which is connected to the PC and see what we get back.

 

The level is around 1vpp but that's why I stated you need the converter to make it 0..5v range. A simple transistor-based switch should work like a 1-bit ADC. My cable company stated there's some sort of "FET/J-FET" switches. If someone is familiar with this jargon here, he can fill us in on what that means and what range of input/output it can handle.

 

If you want to test it, you will have to digitize the analog output back to digital and see if the wave comes back again (or somewhere along the line your equipment distorted it).

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Here's the post I made to a DSP users group a few months ago.

 

http://www.dsprelated.com/showmessage/93148/1.php

 

> Why do you even need to encode the ones and zeros? Couldn't you just

> write the 600 baud, unencoded stream to the CD (I assume around

> 44,100/600 samples per baud)?

 

The audio bandpass filter on typical CD players output won't

pass your data undistorted if the local frequency is too low.

e.g. if any region of data containing long strings of ones or

zeros looks like something below about 20 Hz. You also have

the problem of recovering the bit clock, although that's a

bit less of a problem with a CD than with an old audio tape

drive.

 

EDIT: So maybe it could work if you never had a sequence of ~30 1s or 0s in a row...?

 

Even if we accept that restriction of not allowing <= 20Hz waveform, we still have so much leeway with the -32768..32767 range to just make the 1-bit ADC give a consistent 0/5V output.

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post-7804-1223571790_thumb.jpg

 

This is one I tried - although it's an MP3 being played through my set-top DVD recorder via USB. I did a CDRW with a Wav but it refused to read it, might have been because the disc is kinda ancient).

 

It's just 55 zeros followed by 55 ones (as the Atari would see them) at 44,100 per sec, repeated.

 

So, it seems the playback equipment does reproduce it well although the amplitude drops a little.

 

The Atari uses Start/Stop bits, so you can't ever have >9 bits in a row of the same value.

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The "0, 5 Volt" output isn't such a big issue.

 

The specs allow fluctuation to an extent. The TTL levels Atari and old gear uses specify something like <2 Volts as zero, > 3.5 Volts as one.

 

I think such a system would work. Also, there is scope for speedup. With the standard 1010, I've forced bit rates up around 800 or so. Much above that and we're probably hitting the limits of the FSK decoder in the tape drive.

 

Since a CD-based system doesn't have the demodulation phase, it should go higher.

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Hi guys!

Sorry to interrupt you with such a n00b question: are you talking about something like the CD-Link?

It was popular here in Cz many years ago as it could replace the omnipresent XC12 and relatives and their ever popular Turbo2000 upgrade.

post-9085-1223579216_thumb.jpg

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post-7804-1223571790_thumb.jpg

 

This is one I tried - although it's an MP3 being played through my set-top DVD recorder via USB. I did a CDRW with a Wav but it refused to read it, might have been because the disc is kinda ancient).

 

It's just 55 zeros followed by 55 ones (as the Atari would see them) at 44,100 per sec, repeated.

 

So, it seems the playback equipment does reproduce it well although the amplitude drops a little.

 

The Atari uses Start/Stop bits, so you can't ever have >9 bits in a row of the same value.

 

I think you can't have 9bits in a row of ZERO bits, but ONE bits are okay since they are used for creating space in various IRG modes. Are you sure you can't make the levels closer to their original by adjusting some things?

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