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Salvonline

Atari Jaguar Dsp Jerry version

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Hello, I have an Atari Jaguar with the dsp Jerry half working, I'd like to know if the IC 6SC600HF is interchangeable with the IC TC26SC600HS, because best electonics has only this one.

Thank you.

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Thank you for answering me but I already checked the joints.

The Jerry  processor controls the audio and the controllers as well as other functions, in my Jaguar everything works except the audio, and after checking the entire signal path, I noticed that the signal does not come out of the processor. 

Also this processor is hotter than Tom, which logically should be hotter or the same.

Edited by Salvonline

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Fairly aware of its function (check my sig ;) ). 

 

Have you checked for shorts on the pins also, an increased current draw caused by short somewhere could cause excessive heat.  What kind of temp diff is there? It runs at the same clock as the GPU core, and is a smaller package so it's heat dissipation may differ.

 

Honestly never dug into the physical side of the audio subsystem, is the actual DAC output direct from Jerry? or located elsewhere? The data is sent to the DAC via a serial bus from the RISC core, I don't know if this is decoded within the die or externally.

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The audio DAC is external. There's also a bit of logic to handle the mute feature. But if you don't get I²S signals out of Jerry, there's definitely something wrong.

 

Regarding your chips references, I believe they're the same, but not manufactured by the same company (I think one of them was Toshiba?).

Edited by Zerosquare
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20 minutes ago, Zerosquare said:

The audio DAC is external. There's also a bit of logic to handle the mute feature. But if you don't get I²S signals out of Jerry, there's definitely something wrong.

 

Regarding your chips references, I believe they're the same, but not manufactured by the same company (I think one of them was Toshiba?).

Yes, you are right, I changed tda1545 and 74hc74 then I probed with my oscilloscope the pins SCK, WS, TXD, RXD, directly from the processor.

The only output pin working was SCK, with its square wave.

By the way, jerry reaches 40 degrees while tom is at 30 degrees.

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On 5/14/2021 at 8:47 PM, Salvonline said:

Yes, you are right, I changed tda1545 and 74hc74 then I probed with my oscilloscope the pins SCK, WS, TXD, RXD, directly from the processor.

Sounds like you just changed those devices on a whim without just cause which would be pointless.

Did you check the output of REG 1 is correct?

Is your Oscilloscope fast enough to really see what is going on, ideally you need 60MHz or better.

On 5/14/2021 at 8:47 PM, Salvonline said:

By the way, jerry reaches 40 degrees while tom is at 30 degrees.

I have not measured the temperature of Tom & Jerry with a collection of games to determine typical baseline values for comparison to know if that is indicative of a problem. Without such a baseline I don't think Jerry being a little hotter than Tom really proves anything, if Jerry was up at 60 degrees then things would not be looking so good and at 80 degrees or more then you would definitely have a problem.

Heat is related to work being done so if Jerry is doing more work than Tom then you would expect it to be warmer and whether to not one is working harder than the other will vary.

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hello , I want to update the repair situation, well I found the fault, the problem was a broken track between pin 5 and 13 of the IC U10, the 74hc74. thanks for the help I hope this experience can help someone

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I would like to add a further detail, in the end I bought the TC26SC600HS from Best Electonics hoping that it was compatible.

Well, Toshiba's TC26SC600HS has 144 pins, while the original unbranded 6SC600HF has 160 pins.

After a moment of despair,  looking at the motherboard and the wiring diagram, I noticed that the extra pins are not used and they are external for each side.

I replaced the original chip with the toshiba, and the jaguar works perfectly. 

I wish all of this would help someone.

 

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