exxos's Atari, Amiga & retro forum

Hello guys;
I have a Mega ST that has the TOS error #35.
I have tried another disk drive, another PSU and other TOS chips; but the error persists, does not execute any program or accessory and also when opening windows the files give errors in their names, they change letters for symbols like the arrow.
Any ideas on this fault?
Regards.

Can you format a disk several times with this https://www.exxosforum.co.uk/forum/viewt ... ?f=25&t=52 and post back the results of what happend.

Thanks for answering.
The computer formats and copies disks without apparent errors, but is unable to run any program or accessory. I have tried with disks formatted on the Mega ST, on another Atari and on the PC (of course at 720 Kby).

A friend also pointed to the blitter as a possible cause, but I don't have another chip to prove it.

But have you done the tests I suggested ? I need it proven in FCOPY that you can format reliably several times without any errors before moving onto other things.

That computer cannot run FCopy-Pro or any program, with the Mega ST I can only format from the TOS (and also copy floppy disks). With FCopy I formatted from another Atari and also used the PC to exchange files, everything works in another Atari but not in this Mega ST. :cry:

What floppy drive are you using ?

I would suggest if you haven't a diagnostic cart to check stuff, doing mods 1,3,4 first of all. Possibly 12. Possibly the 1772 is faulty or the cable, or drive.

https://www.exxosforum.co.uk/forum/viewt ... =17&t=1585

You mention blitter.. you can remove it and blob over the 2 solder pads. Though most machines have a blitter patch on the CPU.. but thats another epic. https://www.exxosforum.co.uk/atari/last/MEGAST/index.htm

The floppy-drive installed in this Mega ST is a Sony MP-F11W-UO, it works correctly in another Atari.
Also I installed an adapted PC floppy drive, which is working perfectly on an STe.
Indeed, this Mega STe has a small plate soldered on a rectangular chip (I suppose maybe that elongated chip is the blitter).

If you have a bootable disk in the drive at boot what happens?

PhilC wrote: 07 Nov 2019 17:33 If you have a bootable disk in the drive at boot what happens?

I have not tried with disks with boot sector (as in some video games), but a disc with Auto folder or with accessories causes black screenshots and loop reboots.

When I run a program from a window, it is when I give error TOS # 35. Of course the file is not corrupt, it works on another computer, and the disk drive has already said that it also works correctly on another computer.