exxos's Atari, Amiga & retro forum

I was about to reply exactly the same. You have just hidden your problem.

I connected up my original Falcon with the same SCSI drive and now SCSI copying seems fine...

:WTF:

I will go install HD12.53 because I am even more confused now.

EDIT:

OK nevermind, My original Falcon has 4MB RAM. I guess its why I never saw issues with it all before. I assume if I put a 14MB card in it would also act up the same. Can't be bothered to take it all to bits just for that.

So will wait and see what Jookies test program brings over the next few days. I'm not going to keep spending time on all these stupid problems.

Hmm... this does seem like a software issue. Just because the maximum DMA length is 64K shouldn't mean that SCSI packets are limited to that as many SCSI systems don't even have DMA. For a larger transfer you just do multiple DMA transfers surely? Anyway, knowing the limitation you'd write you code to never exceed that, so again, a software bug.

But if it's a software bug, shouldn't this problem be more widespread? Almost anyone with a Falcon runs with 14mb.

stephen_usher wrote: 23 Sep 2025 14:57 Hmm... this does seem like a software issue. Just because the maximum DMA length is 64K shouldn't mean that SCSI packets are limited to that as many SCSI systems don't even have DMA. For a larger transfer you just do multiple DMA transfers surely? Anyway, knowing the limitation you'd write you code to never exceed that, so again, a software bug.

I don't know.. Don't forget EMUTOS worked worse and that's a whole different OS and driver.

Trying to copy a large file like 10MB fails.. But if I use a 4MB STram card, it works. Which suggests theres a maximum chunk size of maybe 3MB at a guess. HD 12.71 limits to 64KB chunks, so it also works.

Jookies program was for testing cosmosex , he had the exact same issue. I'm waiting for him to patch the program because it was not designed to run on anything else. He says he does not even use a driver. So I guess he just issues raw SCSI commands to the drive.

We may be able to tell more when I can run his program, but I think this is just not going to be resolvable. I cannot even say if it's a hardware or software issue but I would side with hardware currently. But it could may well be a inherent bug in the falcon's logic somewhere for all we know. I have literally zero idea what this problem could be.

Next time you are testing and it fails the copy using GEMDOS/desktop routines try kobold doing the same test using its own routines.

I'm sure sometime ago i read that TOS 4 can have inherent issues with copying large files irrespective of driver?

I had HDDriver v4 back in the day on my 'dodgy' albeit official clock patched bird and kobold always worked.

Steve wrote: 23 Sep 2025 15:04 But if it's a software bug, shouldn't this problem be more widespread? Almost anyone with a Falcon runs with 14mb.

That by itself is a very good question.... But have users been copying large files like 10MB+ on a SCSI drive in the first place ? No idea.

Would probably help of some people could try some large file copies with HDdriver 12.53 (or earlier) to see if anyone else gets the problem.

Maybe its a bug with my SCSI drive... But same thing, wouldn't there be loads of posts about SCSI drives not working right somewhere.. even in the PC world..

I guess I really need to try and find another spinning rust drive somewhere to try..

jwd wrote: 23 Sep 2025 15:12 Next time you are testing and it fails the copy using GEMDOS/desktop routines try kobold doing the same test using its own routines.

I'm sure sometime ago i read that TOS 4 can have inherent issues with copying large files irrespective of driver?

I had HDDriver v4 back in the day on my 'dodgy' albeit official clock patched bird and kobold always worked.

I will see if I can find it and give it a try.. Like I said earlier though, you would have thought EMUTOS would be reliable, but I still have problems with that. It would mean 2 OS's or drives have similar bugs.

KOBOLD died here.

exxos wrote: 23 Sep 2025 15:14

Steve wrote: 23 Sep 2025 15:04 But if it's a software bug, shouldn't this problem be more widespread? Almost anyone with a Falcon runs with 14mb.

That by itself is a very good question.... But have users been copying large files like 10MB+ on a SCSI drive in the first place ? No idea.

If I have time tonight I'll try to chuck around some CDRom images or Tentacle's sound file between IDE and SCSI & see what happens.

BW