Moderator: Atari Frog
No, I only had one original 410 from 1979. I never wanted another tape recorder, EVER AGAIN.Atari Frog wrote:Did any of you notice some tape recorders were more reliable than others? I don't know if this has to do with the head alignment or something else but I found the 1010 would load some programs the XC12 just couldn't handle.
This is not necessarily a bad tape. Some commercial tapes have long gaps, it could be for copy protection and it could be for other reasons as well. Actually, it would be very strange that the signal degraded so much to the point that you get a long gap with silence. Unless, of course, the tape is physically damaged (and not magnetically). But in this case you should be able to visually see the physical damage.phsstpok wrote:I converted two of the six commercial tape without much trouble. Two tapes were unusable. They had huge audio gaps and nothing could be done to save them.
Record in Stereo and NOT in mono. Or at least do as deathtrappomegranate does, just disconnect one of the stereo plugs. What you have been told is indeed true. There are only two frequencies that must be decoded, and if the signal is good that would work even when recording in stereo. But if the signal is degraded, the noise coming from the other channel could make the difference. Furthermore, if your tapes seem to have a very low level, then you will automatically get a level boost by recording in stereo.We discussed stereo vs mono. He explained that one channel has audio and the other has the data but blending both audio channel doesn't affect the algorithm.
If by redundancy you mean error correction, then of course it is not present. Error correction is not present in floppies either (not even in PC ones). There is however a checksum byte on each record, this should be able to detect (but not correct) most errors.There is not much redundancy if any (my speculation not Ernest's words) designed into tape files. Long dropouts means missing data, irrecoverable missing data.
You might be able to recover partial files, specially if they were LISTED. I’m not sure what the format of CAS files is. But you might be able to see the text loading your CAS file with an hex editor. If the effort is worth or not, that’s of course to you to decide.Things that hurt my recovery include using cheap department store tapes 25 years ago, not properly documenting what was on the tapes. For example, some tapes had CSAVEd files, binary load files, LISTed files, SAVEd files, in no particular order. Tape counter numbers did me no good having tossed out my Atari Tape player years ago.
All magnetic media degrade. But tapes usually faster because both the media and the recording system were normally of lesser quality.Tapes do degrade.
Yes, of course. The best ones were the 1010 and the XC11. The XC12 AFAIK was never sold in the USA, and was probably the worst model.Atari Frog wrote:Did any of you notice some tape recorders were more reliable than others? I don't know if this has to do with the head alignment or something else but I found the 1010 would load some programs the XC12 just couldn't handle.
It seems the site is down for good...phsstpok wrote:Did anyone download the entire collection at the CAS Archive? or get a directory list at least? I haven't been unable to get on for weeks.
The XC12 is practical but seems pretty crappy overall. If the tape isn't PERFECT, you know your program will never load...ijor wrote:Yes, of course. The best ones were the 1010 and the XC11. The XC12 AFAIK was never sold in the USA, and was probably the worst model.
Generally since commercial tapes are as long or as short as they need to be I just record the entire tape to the PC. The two bad tapes had spiked noise, data fading in and out of low levels and even silence. Looking at the HEX file produced by WAV2CAS I could see that the recording dropped off mid-data, fading in and out. One tape had visible signs of corrosion or rot. The other one played for about 30 seconds and went nearly silent for the 10 minute length of the tape, except for some spikes. OK it wasn't dropouts.ijor wrote:This is not necessarily a bad tape. Some commercial tapes have long gaps, it could be for copy protection and it could be for other reasons as well. Actually, it would be very strange that the signal degraded so much to the point that you get a long gap with silence. Unless, of course, the tape is physically damaged (and not magnetically). But in this case you should be able to visually see the physical damage.phsstpok wrote:I converted two of the six commercial tape without much trouble. Two tapes were unusable. They had huge audio gaps and nothing could be done to save them.
One of us is confused (probably me). It is my understanding that a stereo tape recorder lays down two tracks in the form of L+R on one track and L-R on the other track. During playback the signals are added and subtracted from one another to produce L+L and R+R, the separate channels. The two tracks do reinforce each other to help with the reproduction of the two CHANNELs. However the signals, orginate as two separate channels, Left and Right. If one channel didn't contain any information when recorded then there isn't anything during playback either. Hence, one CHANNEL will have signal and one won't. You would get no reinforcement by later recording both channels at the PC end. We don't have access to the actual tracks, so we can't take advantage of reinforcement.Record in Stereo and NOT in mono. Or at least do as deathtrappomegranate does, just disconnect one of the stereo plugs. What you have been told is indeed true. There are only two frequencies that must be decoded, and if the signal is good that would work even when recording in stereo. But if the signal is degraded, the noise coming from the other channel could make the difference. Furthermore, if your tapes seem to have a very low level, then you will automatically get a level boost by recording in stereo.
Unless what I said a moment ago is completely wrong it would seem better simply to record one channel in the first place. This is what I meant by "mono". I didn't mean combine the two channels into mono.There is one exception. Some (usually cheaper) third party tape recorders and interfaces recorded in mono. If the tapes were recorded in one of those systems, then you should record the WAV file in mono.
For “converting” from Stereo to mono use any decent Wave Editor. Your sound card probably included one, but otherwise plenty are available. With the Wave Editor delete the “other” channel and convert the remaining one to Mono.
I stand corrected. No reduncy whatsoever.If by redundancy you mean error correction, then of course it is not present. Error correction is not present in floppies either (not even in PC ones). There is however a checksum byte on each record, this should be able to detect (but not correct) most errors.
Actually WAV2CAS produces a hex dump which one can use for analysis. It even has some limited self analysis. At the end of the dump of each record you see either "OK" or "Bad". "Bad" usually means whole bytes were lost. Occassionally the number of bytes is correct but the checksum is wrong. It doesn't matter. Data is lost and there isn't any possibility to recover it from the one file aloneYou might be able to recover partial files, specially if they were LISTED. I’m not sure what the format of CAS files is. But you might be able to see the text loading your CAS file with an hex editor. If the effort is worth or not, that’s of course to you to decide.
All magnetic media degrade. But tapes usually faster because both the media and the recording system were normally of lesser quality.[/quote]True. However, I was somewhat amazed how 20+ year-old, cheap diskettes held up sitting on the basement floor in a cardboard box all this time.Tapes do degrade.
Hmm, I’m not an audio engineer, but I believe you are confused. Stereo analog recording is done with two discrete signals, there is no channel “matrixing”. The mono track is divided in two halves, the left channel is recorded on one half and the right on the other one.phsstpok wrote:One of us is confused (probably me). It is my understanding that a stereo tape recorder lays down two tracks in the form of L+R on one track and L-R on the other track. During playback the signals are added and subtracted from one another to produce L+L and R+R, the separate channels.
This would be true in a perfect world. But there is noise, crosstalk, etc present in an audio signal. So some noise will be always present in the unused channel.If one channel didn't contain any information when recorded then there isn't anything during playback either. Hence, one CHANNEL will have signal and one won't.
Exactly. And the lesser the quality and the level of the “non-empty” channel, the more the incidence of this noise when recording on mono. Furthermore, as we mentioned in previous messages, some commercial tapes have audio on the other channel, which will add interference with the data channel.Listening to the output of my tape deck it is clear that one channel is empty, except for some static and spikes.
This will probably work with marginal tapes (almost good), or even with good tapes that had some small glitches during the WAV recording. Don’t think it will help with badly degraded tapes as you describe.I forgot this earlier but Ernest suggested that if you have multiplie copies of the file you might use a WAV editor to replace damaged areas.
phsstpok wrote:One of us is confused (probably me). It is my understanding that a stereo tape recorder lays down two tracks in the form of L+R on one track and L-R on the other track. During playback the signals are added and subtracted from one another to produce L+L and R+R, the separate channels.
That makes sense to me.ijor wrote:Hmm, I’m not an audio engineer, but I believe you are confused. Stereo analog recording is done with two discrete signals, there is no channel “matrixing”. The mono track is divided in two halves, the left channel is recorded on one half and the right on the other one.
Matrixing is done on stereo broadcastings (TV and Radio) for compatibility reasons. The same stereo signal might be detected both by a stereo or a mono receiver. So the mono signal (L+R) must be transmitted in the usual way. Obviously, it is not efficient two transmit the two channels again separately. So a single extra signal is encoded as L-R that is used by stereo receivers only.
But tape recorders operate completely different. If a stereo tape would be matrixed as you describe, then it would break compatibility with mono. You would hear only the left channel with a mono player (L+R + L-R = 2L). And when using a mono tape on a stereo player you would hear only one speaker (not very desirable).
phsstpok wrote:I forgot this earlier but Ernest suggested that if you have multiplie copies of the file you might use a WAV editor to replace damaged areas.
This much I understood.ijor wrote:This will probably work with marginal tapes (almost good), or even with good tapes that had some small glitches during the WAV recording. Don’t think it will help with badly degraded tapes as you describe.
You don't neccessarily need multiple tapes, but multiple WAV recording of the same tape. "Soft errors" are common and they could be fixed with multiple passes. Soft error is when an error happens by some reason that is not present in another pass. For example, a piece of dust might produce an error but the dust could move to a different position the next time you record.phsstpok wrote:I forgot this earlier but Ernest suggested that if you have multiplie copies of the file you might use a WAV editor to replace damaged areas.
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It also wouldn't be possible with commercial tapes unless one had multiple copies from which to record different WAV files.
I wasn't exactly setting you straightThanks for your help and setting me straight.
Sorry if I sometimes sound a bit harsh. English is not my native language and I sometimes might sound not as friendly as I want.[post edited for clarity]ijor wrote:You don't neccessarily need multiple tapes, but multiple WAV recording of the same tape. "Soft errors" are common and they could be fixed with multiple passes. Soft error is when an error happens by some reason that is not present in another pass. For example, a piece of dust might produce an error but the dust could move to a different position the next time you record.phsstpok wrote:I forgot this earlier but Ernest suggested that if you have multiplie copies of the file you might use a WAV editor to replace damaged areas.
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It also wouldn't be possible with commercial tapes unless one had multiple copies from which to record different WAV files.
I wasn't exactly setting you straightThanks for your help and setting me straight.
Actually, it seems I wasn't completely right. I never used WAV2CAS so I only was talking from theory. For example, I thought that not recording in MONO was critical. From your experience and the one from the WAV2CAS author, it seems it might be important only in some cases.
Probably. Many commercial tapes were recorded in mono.This tape has duplicate copies, one each on the left and right tracks (recorded mono maybe?)
What you can do is to use a Wave Editor, once you have a stereo WAV file. With the editor you can do all sort of conversions, delete one channel, etc.By the way my sound card software appears to combine two tracks to mono when mono recordings are requested. It doesn't let me record left or right independently and so the single cable trick is helpful here.
Hmm. It is possible to have data without checksum. But this requires bypassing the OS and using custom routines talking directly to the hardware. Some tapes use custom blocks as a form of copy protection. This might be the case here. But might me also something else.I've learned from the many load attempts that the program is loading characterset data, and with no form of error checking.
This is what I said in my first message. Some programs won’t work with a SIO2PC cable because the motor control signal is missing. A real Atari can pause and restart the recorder. When using a SIO2PC cable the software in the PC has no way to know the state of this motor control signal. So it happens exactly what you describe. The PC is not pausing, and it sends the data too early.What I think has happened is WAV2CAS has missed a delay gap. I believe this because at one point the "virtual tape" is sending data before the program has requested what it thinks is a real tape player to start.
What were you using if not WAV2CAS?Atari Frog wrote:Hi,
First of all, thanks for contributing again! The tape image will be uploaded tomorrow
I happen to have Crush, Crumble and Chomp! on tape and tried the conversion a couple of weeks ago... without using WAV2CAS.
I already have the first part. I must have most of the last part as what I have begins at lline 10 and continues to what is probably the end of the program. The program appears to end with just a RUN command, as in to simply restart the program.If you have the last part of the program with the data, I can probably retrieve the first and second sections easily (as they are of the standard CLOAD variety).
The program is failing at direct reads of the tape. These are in the form of GET #U3, variable (U3 being itself a variable for the file number). The program is doing these reads in a For..Next loop. I would think timing for this would be critical. Difficult using a real tape never mind simulating it on a virtual tape..Let me know if we can reconstruct the tape version of the game this way...
Ah, I think I understand what is going on.phsstpok wrote:The program is failing at direct reads of the tape. These are in the form of GET #U3, variable (U3 being itself a variable for the file number). The program is doing these reads in a For..Next loop. I would think timing for this would be critical. Difficult using a real tape never mind simulating it on a virtual tape..
