PaulJ's H4 Mongrel Build x 2

PaulJ · Post by **PaulJ** » 06 Dec 2019 16:38

exxos wrote: 06 Dec 2019 16:00 China - self inflicted :lol:

Would help to know if the new DMA circuit works, internal and external.

Yes, I need the hard drive to work and first indications are it doesn't. I did connect the USatan cable to the internal connector and TOS didn't see it. I looked at the donor board and the DMA connector is pretty ratty. Looks like Harry was chewing on it so I may just make an adaptor cable with it to the internal connector so I can connect the Atari DMA test board that runs with the Atari test cartridge. Guess I'll get the meter out while I ponder my course of action. :? Yup I know better with the Chinese crap but one always think they can win the lottery. :mrgreen:

PaulJ · Post by **PaulJ** » 06 Dec 2019 19:56

@exxos it looks like no joy on the ultra satan. Get one flash on the boot but it never see's it. @Icky if you get a chance could you try your DMA port to see if its just me or a board issue? :?:

Post by **exxos** » 06 Dec 2019 20:00

PaulJ wrote: 06 Dec 2019 19:56 @exxos it looks like no joy on the ultra satan. Get one flash on the boot but it never see's it. @Icky if you get a chance could you try your DMA port to see if its just me or a board issue? :?:

I would setup HD10 on a floppy and see if you can find it even listed in the main app first.

PaulJ · Post by **PaulJ** » 06 Dec 2019 21:13

Tried some mapping HD app's but no devices seen. Couldn't find HD10. Going to connect up the cheap DA see if something pops.

Post by **exxos** » 06 Dec 2019 23:17

PaulJ wrote: 06 Dec 2019 21:13 Tried some mapping HD app's but no devices seen. Couldn't find HD10. Going to connect up the cheap DA see if something pops.

Only difference really from the Alpha is the addition of IC6... you could jumper over it, but the same circuit was tested on a Alpha buffer board by Icky I think a while ago. so shouldn't cause any problems.

PaulJ · Post by **PaulJ** » 07 Dec 2019 00:28

Took the DMA connector off an old board and installed it. Connected the test board and tested serial, ROM, MIDI, Printer/Joy ports, DMA, and High REs. These all pass with the exception of DMA. See attached picture. Suspect D3 is the real issue. Will be investigating.

D1D3.jpg

IMG_2346.jpg

Post by **Icky** » 07 Dec 2019 10:15

@PaulJ - Have just plugged my US in and its not recognised. ACSI bus is but not the device. Will investigate today.

PaulJ · Post by **PaulJ** » 07 Dec 2019 14:26

Icky wrote: 07 Dec 2019 10:15 @PaulJ - Have just plugged my US in and its not recognised. ACSI bus is but not the device. Will investigate today.

Yes @Icky , that's the same indication I get with the driver utility. I used Saleae software with the crapy Chinese DA hardware imitation for a quick look comparing Atari DMA board between a working and not working system. Using the test I always get the same transfer test. It looks like HDCS is missing so I'm going investigate it. Not much there, strait shot from DMA chip. Do you know of a description of the hardware handshake? If I don't find something I'll have to figure out how to use the HP digital analyzer.

Not Working.

C2NW.jpg

Working

C1NW.jpg

PaulJ · Post by **PaulJ** » 07 Dec 2019 14:39

Just checked from DMA chip P24 to pin 18 on mega dam connector and its open. Unless I screwed up somethings wrong here. Ops cockpit error. It's ok. :oops:

Post by **Icky** » 07 Dec 2019 14:44

@PaulJ - I have jumper over buffer and that made no difference so its not the buffer.

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PaulJ's H4 Mongrel Build x 2

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