exxos's Atari, Amiga & retro forum

something is not right yet the partition on the Ultrasatan is defective after the one-time start, tried several times, the same thing over and over again. How is the Ram of the TK integrated automatically?

can it be that the Atari Mega ST are miserable bitches? I've done a Mega ST2 fixes so far but only the Atari logo comes, no Ram test, no booting from drives.

ottifant011 wrote: 04 Oct 2022 21:17 can it be that the Atari Mega ST are miserable bitches? I've done a Mega ST2 fixes so far but only the Atari logo comes, no Ram test, no booting from drives.

I have said it before that the MEGA ST is the worst machine for doing absolutely anything with. But all the all ST's are not great either. I tend to use the STFM 70789 motherboards as my "stock original" machine as I found it to be the most stable. It's all why I gave up in the end and developed the H4 / H5 platform because 95% of my time is taken up chasing stupid faults rather than developing hardware.

I did notice you have the MMU & CDIS jumpers closed, not sure why ?

Looking at your motherboard you seem to have all IMP chipsets. So my only suggestion would be to swap them out for the Rioch based chips which are normally in STF machines and see if that helps. Changing the GLUE & MMU might be enough.

Looking at my MEGA ST RESULTS It seems the closest board I had was REV2.1 Where I documented that it was unstable with a simple 16MHz accelerator using IMP chips. I also documented a lot of troubles with the 16Mhz clock from the shifter to MMU.

My Mega STs work great with the in built IDE drive but not so well with an Ultrasatan and no matter what I do my floppy either hardly works or not at all.

So I would suggest that if using a Mega ST then get used to using IDE built into the ST536 and have a dos swap partition on your media device for file transfer.

I do need to diagnose why my two Megas hate their floppy drives at some point. I really also like the Mega format, just a shame they are so unreliable which gets worse as they get older.

I have the 3rd Atari Mega ST2 with 4MB Ram on the table, same picture as in the 1st Mega ST1.
boots 1 time from the Ultrasatan and then lights up briefly and closes.
I once ordered the SN74ABT244 let's see if something improves

ottifant011 wrote: 05 Oct 2022 19:21 I once ordered the SN74ABT244 let's see if something improves

Generally putting faster chips into machines is a bad thing. You're better sticking to LS chips. More noise immune.

PhilC wrote: 04 Oct 2022 21:47 My Mega STs work great with the in built IDE drive but not so well with an Ultrasatan and no matter what I do my floppy either hardly works or not at all.

So I would suggest that if using a Mega ST then get used to using IDE built into the ST536 and have a dos swap partition on your media device for file transfer.

I do need to diagnose why my two Megas hate their floppy drives at some point. I really also like the Mega format, just a shame they are so unreliable which gets worse as they get older.

I can pile on to what Phil's experience is here as well. My Mega ST works fine with the Ultrasatan running on the original 68k. Once I switch to the TF536, I can only occasionally get it to "see" the hard drive and read data on it. Any attempt to write to the US results in crazy weird errors. Running from the built in IDE works like a charm and is perfect. Only downside is I now have to open up the case to copy to the CF card (yes, there are plenty of ways to run extenders, use netusbee etc...I just haven't gotten to those options yet).

how does it work with the IDE? setup like the Ultrasatan? Do you still have to lay cables to the board? So far I haven't had any success booting and I don't think TK Ram is available or I don't know how to integrate it.

Sorry, I'm not very familiar with Atari OS, I'm more from the Amiga scene

IDE is simple. Just partition like you would with HD11 driver etc.


No idea why people struggle with Ultrasatan. I've not had any issues but I think I may have only tried on the H5. Next time I find my working STFM board, I will try ultrasatan on that. But IDE is just easier than messing about anyway.

many thanks for the help.
does the gray cable have to be connected to ACSI10 for ide to work? If yes, where? TT Ram works!!! Bombs fly when I activate blitter.