exxos's Atari, Amiga & retro forum

Hi, just doing some work on Paradroid STe with the infamous DMA issues writing to Ultrasatan. He has the 32mhz accelerator installed. I am looking to geogeo's recent thread for guidance as he managed to solve his problems: https://www.exxosforum.co.uk/forum/viewt ... 1&start=20

So far:
* P100 resistor array is 2.2k, so will swap this to 1.2k
* Remove the other resistor arrays as recommended
* Socket DMA to try different chips
Oh bloody hell how am I going to get these resistor arrays out with the 32mhz booster over the top and soldered into place... With a lot of careful patience, desoldering gun & flux & wick I carefully managed to remove them with some tweasers. Just a check to see if everything is still working:

Steve wrote: 02 Feb 2021 19:43 Hi, just doing some work on Paradroid STe with the infamous DMA issues writing to Ultrasatan. He has the 32mhz accelerator installed. I am looking to geogeo's recent thread for guidance as he managed to solve his problems: https://www.exxosforum.co.uk/forum/viewt ... 1&start=20

He didn't though ? He still has issues ?

geogeo_28 wrote: 01 Feb 2021 18:39 I can claim victory on the floppy read/write at 8/32MHz but for the UltraSatan I spoke too fast.
The irony is, with the UltraSatan, at 8MHz I still experiencing data corruption on write but no issue at all at 32MHz.

Oh ok well... I'll just do what I can and see if my results are different to geogeo's. @exxos do you recommend running with the address bus resistors removed like this or shall I try 2.2k also.

If the booster is in, then remove the MB roms...

*IF* They are all 10K they could be left in... I can't say for 4.7K ones.. Best to remove them...

As a side note, are people using a good PSU for ultrasatan ? as "chargers" can cause all sorts of chaos..

I've also found the ACSI cable to be extremely important to the reliability of 3rd party ACSI devices. 20 cm ribbon cable seem to be more or less a maximal length. Also, the crappy fake Apple/Samsung USB chargers often bundled with various 3rd party devices are causing problems. Use a good quality PSU, or at leas a genuine Apple/Sony/Samsung USB charger to power your UltraSatan.

This Ultra is internal and powered from the motherboard. So no dodgy external power.

UPDATE ON TESTING:

TRIED WITH TWO DMAS:

DMA - CO25913-38 PH23-030 / 8M4 44

RESULT: 8Mhz write corruption / 32Mhz write corruption

DMA - CO25913-38 PH23-030 / SJ4 95

RESULT: 8Mhz write corruption / 32Mhz OK

Cannot tell, but does not look like the DMA pullups are fitted?

I'll try that next @exxos cheers

Just double check, you mean the 10k pullups on the WD1772 chip? https://www.exxosforum.co.uk/forum/viewt ... =17&t=1417

Steve wrote: 04 Feb 2021 11:04 Just double check, you mean the 10k pullups on the WD1772 chip? https://www.exxosforum.co.uk/forum/viewt ... =17&t=1417

Yep.