The gigafile did odd things. Sometimes it was 3.3V and other times 5V. I assume when it was driving the bus it was driving 3V by itself and not relying upon the pullups. I know Wolfgang had a lot of problems with the thing overall. Possibly he was driving the bus because the pullups were just inadequate to drive a logic high. And by adding the pullups solved a great many problems. So it would seem logical in driving 3V from gigafile in that respect. But things are slightly more complicated on the STE.
- d2.png (7.14 KiB) Viewed 2091 times
All here, but note that is all very old research and invalid these days. Likely that page will be taken down in the future anyway.
https://www.exxosforum.co.uk/atari/last/ ... /index.htm
In any case, I do have the original black box ultrasatan is the one I generally use. I do have the updated one in the grey metal box but I have not used that one much because the case seems to be "live" :roll:
With so many clones of hard drives out there these days it is becoming increasingly difficult to work out what is wrong with the things. But realistically, the people developing the hardware should figure out the problems with it all.
- Capture.PNG (68.28 KiB) Viewed 2091 times
Indeed its clamped to 3.3V. But via a 220R. With pullups (DMA FIX) it would be like 10K clamped to 3.3V. But with driver chips like on the STE, 5v driven via 220R is like 22mA.. 114mW. Might be lower as I think the STE had 33R in series as well.. To lazy to check.
Not sure I follow why the 100R are in there. If its hard clamped to 3.3V, then you only need to drive low anyway. Maybe just noise immunity. No point in a voltage divider if your hard clamping to 3.3V anyway. I am assuming the chip is running on 3.3V. Even so, if the chip is driving high, then the 100R may make more sense as the chip voltage might be higher, say 3.5V depending on regulator tolerances. But anyway, getting off topic a bit.
So as
@stephen_usher mentions, 10K DMA pullups will have no effect on the STE in terms of voltages on the ASCI bus. But the DMA pullups are for the DMA IC side of things, like the floppy drive also. 10K on the STFM still won't effect the ASCI port as its still clamped to 3.3V. But the fix should still be done for the floppy drive anyway. If ultrasatan is driving a logic high, then it would probably work more reliable on a STFM as it will be basically circumventing the 10K DMA pullups.
As I was testing my ultrasatan originally on my STFM, I will make the assumption that UltraSatan is not driving a logic high but relying on the pullups. If it was driving high then I probably would not have came conclusion that the 10K DMA pullups were needed to fix the problems with it. Of course I am reeling this off the top of my head I have not looked into all this for a long time.
I don't know what Lothrek did changes wise over the original ultrasatan design ? I think I might have taken mine apart and took a image of the PCB at some point, cannot remember. But I think we have all had this discussion before somewhere.
TL;DR:
People should still do the 10K DMA pullup fix. Its a known point of failure, so just don't risk it.
Disclaimer :
As to if it will specifically solve your hard drive problems or not I really cannot say. There are that many clones and hard drives out there now, some of them have been manufactured bad out of the box. Some people may have bad connections, bad power supplies, bad SD cards, the list is inherently endless. The fixes I came up with solve a lot of known problems. They cannot of course fix " unknown to me" problems. Like I said some years ago, the faults on these machines are developing faster than I had time to investigate them. Hence why I gave up and just developed a new motherboard.