+Allan Posted June 24, 2018 Author Share Posted June 24, 2018 After making sure the cassette would load on my 410, I did number one and two with Space Chase. Hopefully it helps. I will go back and try them on some of the cassettes that would not record well. Allan Space_Chase_APX.flac.zip 2 Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted June 26, 2018 Share Posted June 26, 2018 (edited) Great quality recording, zero problems when converting. It would seem that developing a utility for recovering of data from cassettes and let others to use it is just a very small first step. The second step is becoming an expert on tape restoration. The third step is using your own tool to restore the data in an expert manner. What to say, Kr0tki? Amazing job with the A8CAS project and tape restoration in general! Well, thank you, that's kind of you. Me being the most proficient user of A8CAS should not surprise anyone, considering I still haven't motivate myself to write detailed enough documentation for other to use Does the existing Wav2Cas and similar software do a comparative analysis to detect and compensate for tape stretch? Given that we're only dealing with 2 frequencies it shouldn't be something that's too hard to do. This feature is not yet included in any CAS converter, but it's doable. But in reality, in all those years I haven't yet encountered a tape that showed any symptoms of stretching. In the quite rare cases of warping, it was always caused by a problem with the tape deck. Considering that such recordings do not qualify for preservation purposes anyway, the best solution in such cases is to re-dump the tape using a better tape player. So, while this feature is on my to do list, its priority is very low. Space Chase (1981)(APX)(US)BASIC.zip Edited June 26, 2018 by Kr0tki Quote Link to comment Share on other sites More sharing options...
+Allan Posted June 26, 2018 Author Share Posted June 26, 2018 Thank you, again, Kr0tki. Your cassette/CAS skills are amazing. Allan Quote Link to comment Share on other sites More sharing options...
80s_Atari_Guy Posted June 26, 2018 Share Posted June 26, 2018 I love reading this stuff. I have many old tapes on many different platforms (Including Synthesizers) and have always wondered how to do this reliably. Given that we're only dealing with 2 frequencies it shouldn't be something that's too hard to do. Are they still 2 distinct frequencies once they're converted to digital ? In the analogue domain, you would have 1 frequency for the recording, and one from a mechanical problem. In the digital domain, would software be able to tell which is which ? Genuinely interested. Quote Link to comment Share on other sites More sharing options...
+Allan Posted June 26, 2018 Author Share Posted June 26, 2018 I re-recorded Player Generator after cleaning the pad and rewinding it with a pencil a few times. I was able to load the wav file into Altirra without a problem. Allan Player_Generator_APX.flac.zip 1 Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted June 27, 2018 Share Posted June 27, 2018 Yup, the recording is good enough now. The warping has not been completely eliminated, as there remains some rapid speed fluctuation, and the overall pitch gets progressively lower the closer to the tape's end, but the issue not severe enough to pose a big problem. With some manual help, the conversion ended successfully. The version number and date in the filename are taken from comments in the BASIC listing. Player Generator v3.20 (1981-10)(APX)(US)CLOAD+RUNBASIC.zip 3 Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted June 27, 2018 Share Posted June 27, 2018 Are they still 2 distinct frequencies once they're converted to digital ? In the analogue domain, you would have 1 frequency for the recording, and one from a mechanical problem. In the digital domain, would software be able to tell which is which ? Genuinely interested. Not sure if there's some misunderstanding. Atari programs are stored on tape as a single sine wave with frequency alternating between two values, 5327 Hz and 3995 Hz, to represent digital ones and zeroes, respectively. Conversion to digital form does not destroy this signal. Quote Link to comment Share on other sites More sharing options...
80s_Atari_Guy Posted June 27, 2018 Share Posted June 27, 2018 What I meant was, if you are getting a 2nd frequency from problems with the equipment, or the recording, would software (used to correct the recordings) recognize the two frequencies ? Sorry if it sounded confusing, I was just interested. I do lots of VHS restoration, and when you capture VHS recordings, if you also capture noise (a separate frequency) once digital it's no longer noise, just pixels. So you can no longer separate the noise from the recording, only use plug-ins to smooth-over the noise which then slightly blurs the final recording. Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted June 28, 2018 Share Posted June 28, 2018 I'm still confused. The speed issues in the tape recorder do not introduce any second frequency into the signal. They cause the original sine wave to shift its frequency lower. That frequency shift can be determined algorithmically without much problem. Quote Link to comment Share on other sites More sharing options...
80s_Atari_Guy Posted June 29, 2018 Share Posted June 29, 2018 I wasn't talking about tape speed, which I'm fully aware wouldn't introduce a second frequency. I was talking about hum, buzzing, noise, etc.. generated by the analogue audio equipment. The second frequency would be the hum, buzz, noise, etc.. Don't worry about it. I know what I was on about, and this is now way off topic. Quote Link to comment Share on other sites More sharing options...
+Allan Posted June 30, 2018 Author Share Posted June 30, 2018 I've been working on making some Flac recordings. Here's APX Downhill. I got the wav to load in Altirra. Allan Downhill_APX.flac.zip Quote Link to comment Share on other sites More sharing options...
+Allan Posted June 30, 2018 Author Share Posted June 30, 2018 I made one of Buried Bucks and it seems to have some issues. Any suggestions by looking at the recording? I pencil-rewinded about five times but it still looks like it has issues. I did a couple more but they are over 50MB so I will have to post them somewhere else. Allan Buried_Bucks_ANALOG_Software_back_side.wav.zip Quote Link to comment Share on other sites More sharing options...
Fred_M Posted July 2, 2018 Share Posted July 2, 2018 (edited) Here is downhill. Downhill_APX.rar Edited July 2, 2018 by Fred_M 1 Quote Link to comment Share on other sites More sharing options...
thorfdbg Posted July 2, 2018 Share Posted July 2, 2018 This feature is not yet included in any CAS converter, but it's doable. Actually, this is included in my wav2cas converter. It automatically selects the filter pair that provides the best recognition rate, evaluating the recording with all possible filter pairs available. This is also necessary to a certain degree as tape speed (not so much tape stretching) varies over time. 1 Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 2, 2018 Author Share Posted July 2, 2018 Here is downhill. Thanks, Fred_M. Allan Quote Link to comment Share on other sites More sharing options...
thorfdbg Posted July 2, 2018 Share Posted July 2, 2018 I wasn't talking about tape speed, which I'm fully aware wouldn't introduce a second frequency. I was talking about hum, buzzing, noise, etc.. generated by the analogue audio equipment. The second frequency would be the hum, buzz, noise, etc.. Don't worry about it. I know what I was on about, and this is now way off topic. The wav2cas decoder, similar to the real-world decoder, depends on two band-pass filters. As long as the noise is additive, such noise will typically be filtered out by the band-pass filter pair anyhow, so it should not matter. It becomes more complicate if the nosie is of a different nature and interference creates alias frequencies in the same frequency range than the two tones. 2 Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 2, 2018 Author Share Posted July 2, 2018 My mistake. Ignore if anyone saw the previous post I made. Downhill works fine. On another note. I just did Let's Play by PDI but it's a two-track program with voice. It's too big to post here so I will post it somewhere else and include a link. Allan 1 Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 2, 2018 Author Share Posted July 2, 2018 I took some screen shots from Let's Spell. http://www.atarimania.com/game-atari-400-800-xl-xe-let-s-spell_2971.html I just have to record the other side. Allan 1 Quote Link to comment Share on other sites More sharing options...
Fred_M Posted July 2, 2018 Share Posted July 2, 2018 I made one of Buried Bucks and it seems to have some issues. Any suggestions by looking at the recording? I pencil-rewinded about five times but it still looks like it has issues. I did a couple more but they are over 50MB so I will have to post them somewhere else. Allan Between 2:01 and 2:02 there is a small drop in the audio. I cannot fix that, but maybe Kr0tki can. Also between 3:46 and 3:48 is a big audio loss. Looking at the audio, it is possible that the program ends at 3.46 and the rest is a different program. But I cannot check that, because the audio drop at 2:01 makes the file unreadable for me. Your audio files are a bit low in volume by the way Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 3, 2018 Author Share Posted July 3, 2018 Between 2:01 and 2:02 there is a small drop in the audio. I cannot fix that, but maybe Kr0tki can. Also between 3:46 and 3:48 is a big audio loss. Looking at the audio, it is possible that the program ends at 3.46 and the rest is a different program. But I cannot check that, because the audio drop at 2:01 makes the file unreadable for me. Your audio files are a bit low in volume by the way I had the audio out on my deck almost cracked to the highest and the input volume on Audacity at 93. I will turn them even more to see if that helps. Allan Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 3, 2018 Author Share Posted July 3, 2018 I made another copy of Buried Bucks after 'Pencil-rewinded' a few more times and turned up the volume. Allan Buried_Bucks_Copy_2.flac.zip Quote Link to comment Share on other sites More sharing options...
Fred_M Posted July 3, 2018 Share Posted July 3, 2018 Here you are Allan, This time success! As I expected, the part after 3.46 is a different recording (luckily!). I enhanced the volume in Audacity and now Buried Bucks is loading :-) Buried_Bucks_Copy_2.rar 1 Quote Link to comment Share on other sites More sharing options...
+Allan Posted July 3, 2018 Author Share Posted July 3, 2018 Thank you again, Fred_M. Allan Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted July 4, 2018 Share Posted July 4, 2018 Hey Fred, the Downhill, tried on Altirra as I don't have a cassette for the real Atari and no easy way to even make a tape I only tried XL mode and after the main boot and it got past the CLOAD and the run it gave a couple of errors...Just to save me looking, is it 800 mode or awkward about basic version? Cheers...Normally I'd check but I seem to have a whirlwind life of looking after every one I know, love doing it but I'm busier than I can cope with Quote Link to comment Share on other sites More sharing options...
Fred_M Posted July 4, 2018 Share Posted July 4, 2018 Hey Paul, You are right. I CLOADed the program and it loading fine. I never saw that it tries to load a second stage. I will have to take a look at it, to see what it is trying to do. Quote Link to comment Share on other sites More sharing options...
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