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1010 tape silence on 800xl+vbxe/stereo/u1mb/sio2sd


wesmond
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Hi all,

 

I have an 800xl upgraded with VBXE, Stereo Pokey, U1Mb, and an internal Sio2Sd. And I also have an 8-year old (human) who actually might enjoy "Invitation to Programming", so I've plugged in the 1010. Motor control works fine, (eg, CLOAD or POKE 54018,52) - but I'm just hearing dead silence - none of the familiar loading noises, nor any audio that's on the other track with tapes like that. I cleaned the heads, even though I felt grubby heads would at least give me some sort of noise. I did some SIO cable wiggling, and then tried a different SIO cable. Then I tried a second 1010 - all making no difference.

 

So, I'm thinking it must be down to the 800xl itself - maybe some side-effect/issue caused by the upgrades it's got - which all work perfectly and were expertly done (not by me! I'm happy with a multimeter, and buliding new kit, but didn't think I'd manage un/soldering on the 800xl board...)

 

I appreciate it's a bizarre combination - having all these upgrades, and then trying to load from tape. But does anyone know any reason why this shouldn't work - or where I might start on diagnosing it?

 

Thanks,

Wes

 

 

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Ok - I could listen to the audio on the old monitor DIN (no RF modulator any more). I'm currently viewing/listening through VBXE->SCART.

 

However - I somehow failed to mention in my first post that data loading isn't working either - I eventually get some sort of tape read error code, so whichever part of the Atari that's listening for what the 1010 gives, is I think not getting it.

 

And also, a last restort, I checked the tape itself has content with an ancient walkman, and it does..!

 

W.

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1.Are you using actual tape on a real tape recorder? .cas images do not contain audio tracks unless you downloaded the audio separate and reconstitute....

2.When is the last time you cleaned the cassette decks head?

3.Did you try the other loading methods on cassette ie..

   a. CLOAD                       loads programs saved with CSAVE   b. LOAD "C:"                   loads programs saved with SAVE "C:"   c. ENTER "C:"                  loads programs saved with LIST "C:"   d. RUN "C:"                    loads&runs programs saved with SAVE "C:"

remember to load machine language progs with start and option held at the same time while powering up then press the key to begin loading

 

remember to rewind tape, some times too much leader space or too little lead in time causes problems....

 

If you have audio off the Atari but not the add on, recheck your wiring and the upgrade...

Edited by _The Doctor__
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Hi _The Doctor_,

 

Afraid it's a bit lower level than that - it's real tape, and I'm getting really dead silence, rather than the kind of noisy stuff you get with dirty heads, or the data errors you get when you try to load the wrong sort of data.

 

Will be having a look at the SIO/stereo Pokey wiring first and see if anything looks interesting...

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Hi all - just for info, the problems I had are resolved - it was a slightly confusing combination of:

 

1. As Brentarian/FJC were getting at, tape audio (both the data whistle, and any music/voice track) come through my Din5 monitor port's audio, but not through my VBXE port's audio, which I'd been using. My VBXE port only gives me OS-generated tape sounds which it makes when it's successfully reading blocks. (Unless I do POKE 65,0, in which case I get absolute silence, but the data still loads fine - if the tape is good).

 

2. Combined with that, the first tape I was testing on was not so good, and was causing a "genuine" data error. Through the Din5 port when that happens, you hear some slightly rubbish data noise, whereas through the VBXE port, the OS doesn't generate anything, so you hear nothing tape-related...

 

So, all is well - but I suspect the bizarre combination of viewing VBXE graphics, while also listening to the audio-track of a tape loading is not possible... !

W.

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I'm still a little puzzled about this. I just checked out the 800XL schematic and four audio sources (external audio, SIO audio, bell and Pokey sound) appear to get mixed together quite late in the circuit. Now, GTIA bell (for the console audio, i.e. key click) is picked off by the Stereo Pokey board, so the stereo audio off the dual Pokey is guaranteed to carry the key click noise, as well as any OS (i.e. Pokey) generated SIO noise. But I'm starting to wonder about SIO audio-in and external audio in being left out in the cold.

 

To clarify, when I wire up a DIN13 RGB jack on the back of one of these VBXE A8s, how the audio is wired up depends on whether there's a stereo Pokey board present. If there is, the L/R audio pins are wired straight to the stereo Pokey L/R audio out, and this is how your machine is wired up. So - you get GTIA and Pokey sound out of the DIN13. If there's no dual Pokey, the legacy video jack's audio pin is simply jumpered to both L/R audio out on the DIN13. I'm starting to think that the latter is the only way to get SIO audio-in and external audio in to come out of the DIN/SCART lead.

 

Of course, you can't just go jumpering extra stuff after the fact. The other audio sources would need to be accounted for and mixed down by the dual Pokey board. I suppose this could all be verified by testing the audio track on a tape with a stereo and a non-stereo equipped machine, but while I have a few tape decks, I got no tapes. :)

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My guess is that the modified audio only has the POKEY output and not the analog cassette output. So far every video upgrade I've seen gives guidance to hook up the POKEY audio and neglects the cassette analog audio to the new AV jacks.

Edited by ACML
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Yeah, that makes total sense FJC - if you'd installed VBXE on a machine with stock mono Pokey, you'd pick the audio lines that mixed all 4 signals for the final audio out. Obviously if stereo-pokey is there, you'd want to take the audio from that, but stereo pokey by design doesn't pick up those two channels. So in an ideal world, the stereo pokey board would take all 4 inputs in, and they'd emerge mixed via the stereo output you wire to the VBXE port.

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What about strapping a tiny cheap circuit somewhere in there, that mixes GTIA Bell, External Audio and SIO Audio, and puts that into the stereo board, instead of just the GTIA Bell that it currently picks... something like an LM3900 chip, and try to copy the mixing behaviour a stock Atari has. (example circuit http://www.circuitstoday.com/multi-channel-audio-mixer-using-lm3900),which doesn't sound too demanding....

 

The other thing I suppose we could do is... disconnect Pokey output from the input of whatever circuit does the mixing in the stock Atari, and disconnect output of that mixing circuit from the Monitor DIN. Instead, feed output of the stock mixer into the GTIA Bell line that goes into stereo pokey board. Then connect output of the stereo pokey to both VBXE port, and I guess one channel of it to Monitor DIN audio.

 

But these are all layman ideas - I loved electronics in school, but haven't used it in 20 years, and even then, not very much! And this is all rather theoretical though, to fix a very unimportant problem! Perhaps this is really to answer the question "What's the absolute perfect complete backward-compatible way to do this" should someone have a stereo pokey/vbxe upgrade to fit in the future.

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I don't have a VBXE, but I do have the dual POKEY mod. From my experience disk and tape I/O still comes out one of my L/R audio outputs, but for sounds like the key-click I still use my audio out on the DIN (and also for a "center channel speaker") in my set-up. I'm planning on modding my 1200XL with an internal speaker for key-click, etc. like the 400/800.

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That's another nice workaround, - just mix stereo out and add Din5 mono in the centre! Could either do that internally, or externally...

 

Interesting - perhaps your stereo mod was wired differently to mine, and instead of picking up GTIA bell, it took one of the external/SIO audio lines - assuming you're getting full tape audio out of the stereo board, and not just the pokey-generated part of that. (Disk IO sound is totally pokey-generated isn't it? - so that should come through all the outputs)

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I have not tried to load tapes with audio lines. All I have are half a dozen standard single load games.

 

As too my dual-POKEY upgrade, it's the original "Gumby" piggy-back mod and all my stereo audio comes directly from the pins on the POKEYS. The mono channel routes the usual way through the mobo to the DIN5. But I will double check on tape data noise coming from one of the stereo outs, I may be mistaken and it's only the mono channel.

 

I also have one of MetalGuy66's dual-POKEY boards and it seems to work exactly the same, but it wouldn't fit in my 1200XL next to my Atarimax Warp+ OS board when I wanted to install it. I couldn't locate the proper socket connector to use a ribbon cable and put the stereo board somewhere else, so I just did the traditional piggy-back instead.

Edited by Gunstar
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