Mega STe stability issues.

[exxos]

Give this a try https://www.exxosforum.co.uk/forum/viewt ... =17&t=1484

[troed]

Did you make any modifications to the MSTE when you first installed the MonSTEr perhaps? ("To get the blitter working") I think.

http://www.fairlite.co.uk/AtariKit/mons ... olders.txt

[Dbug]

Did you make any modifications to the MSTE when you first installed the MonSTEr perhaps? ("To get the blitter working") I think.

http://www.fairlite.co.uk/AtariKit/mons ... olders.txt

Not really modifications, it's just soldering wires on some pins to connect back to the card, no cut tracks or anything like that, in theory removing the card just means I have a wire harness with 5 pins not connected to anything.

[Dbug]

The ATI cards (mach32/64) are very power hungry and can cause voltage drops. I had some stability issues with a mach32 until I soldered a +5V and GND connector on the nova ISA connector board. Delivered voltage went in my case from 4.5 to 5.05.
ACSI/DMA is always a trouble maker. Shorten the ribbon cable you got from lotharek as much as possible, just make sure you can still open your drive bay to access your ultrasatan.

So I measured the voltage on the pins of the ISA connector.

I have +4.89v, -12.65v and +12.09v respectively for the +5, 12 and +12, and nothing at all on the -5v (which I believe is only required for some very rare cards so should be ok?)

Do these voltage seem ok?

[Dbug]

I've to admit that I suck as soldering, but as far as I can see there's no contact between the pins, so theoretically they should not impact the CPU running without the MonSTer card... except that still does not work even after having tried to bend the CPLD socket pins.

Anyway, here are the 5 wires soldered on the components:

image_2022-04-28_191842030.png

image_2022-04-28_191851755.png

Still digging.

[Dbug]

I'm a moron...

I had to remove the TOS to be able to use the MonSTer flash TOS feature... I guess a ST does not boot without the ROM

[frank.lukas]

The ATI cards (mach32/64) are very power hungry and can cause voltage drops. I had some stability issues with a mach32 until I soldered a +5V and GND connector on the nova ISA connector board. Delivered voltage went in my case from 4.5 to 5.05.
ACSI/DMA is always a trouble maker. Shorten the ribbon cable you got from lotharek as much as possible, just make sure you can still open your drive bay to access your ultrasatan.

So I measured the voltage on the pins of the ISA connector.

I have +4.89v, -12.65v and +12.09v respectively for the +5, 12 and +12, and nothing at all on the -5v (which I believe is only required for some very rare cards so should be ok?)

Do these voltage seem ok?

The +5 volts is fine. The +5 volts have to go over the mainboard and the ribbon cable to the VME backplane and through the Nova adapter and over 30cm long ribbon cables to the ISA slot. The +5 volts drop a bit, which is okay and quite normal. It's not a problem either.

[Dbug]

The +5 volts is fine. The +5 volts have to go over the mainboard and the ribbon cable to the VME backplane and through the Nova adapter and over 30cm long ribbon cables to the ISA slot. The +5 volts drop a bit, which is okay and quite normal. It's not a problem either.

Thanks!

So, after putting the original ROM back (good old French 2.05), the 68000 (the low power version), the machine finally starts fine, and with the Mach 32 installed the same Kronos crash still happens, so I guess that was not the MonSTer card causing the problem.

I had a second set of SIMM, which I swapped with the existing ones and ran YAART again, no problem found on these either.

Now, regarding the "go back to stock to see if that works", yes the machine works stocks, the issue is that:
- Kronos only crash when I'm in 800x600x256, so I need the graphic card installed
- Kronos does not fit on a floppy, so I need some mass storage (in my case, all I have is the Ultra Satan, still with the long flag cable)

Not sure what to try next, the other suggestions I can remember were:
- Shortening the Ultra Satan cable
- Replacing the bus resistors
- Replace the drivers by some other (I'm now running with Idek+NVDI, no change)

[mikro]

You mentioned other issues - like failing boot, the freeze in steno, ... You said that the boot issue happens only with the graphics card. Does it happen also without Monster? There's still a lot of testing left...

[frank.lukas]

If the MSTE had 4MB ST Ram the MonSTer can provide 6MB Alternate Ram max because of the Nova VME.