I would recommend SerialDisk as an alternative to GhostLink: https://github.com/z80andrew/SerialDisk SerialDisk emulates a folder on a PC as a FAT16 disk drive on an Atari computer running TOS via a serial link. Simply put, it provides an easy method to transfer files between a PC and an Atari ST/TT...

Sounds like a bus loading issue again, did you try changing the pull ups ? At first I wanted to fix the issue with "plug and play" solutions before heating up my solder iron. So actually I did not add the pull ups. It runs fine on my BLiTTER enabled 1040STfm. Great! Thanks for the report.

Here's a test version of the "Fast Bobs" demo for Blitter equipped Atari STs. Please let me know if there are issues on real hardware.

Steve wrote: ↑Wed Jul 29, 2020 10:33 pmThat is awesome news! Perhaps this new chip uses slightly less power or something.

Thanks.

I ran two more tests lately and everything works as expected. So finally I would say that the CPU change indeed fixed my issue.

Thanks for your comments. I have changed the RAM modules but the glitches remained visible. The inserted modules have parity chips as well but I wanted to check out another fix before cutting traces. So actually I have replaced the CPU. The old type was an MC68000FN8 and the new one reads MC68HC000F...

Image of the mainboard:

RAMs (is the type a possible source of the issue?):

exxos wrote: ↑Fri Jul 24, 2020 11:16 am Have you changed the bus pullups ?

No, not yet. I‘ll have a look on the mainboard today if there is something suspicious.

Today I checked when the issue appears after a cold start and with the new PSU it returns after about one hour.

Hi Sasha In your first post you mention replacing your psu with a new psu - just to clarify, what was the new psu? A completely new model or a new old stock etc? I ask because if you replaced it with an original model, the caps could still be 30 years old. And besides that I would recommend the DMA...

Damn. After replacing my floppy disk drive with a Gotek device the issue is back.

I need to add that I have an IDE „backpack“ solution installed which works fine so far all the years. Probably I need another DMA hardware fix like the pull-up resistors on the bus?!