Troubleshooting STFM with white screen

[Slartibartfast]

Yes the Sony drive is a 1.44 version however I cant turn over the connector as it’s keyed and the other end is soldered to the Atari motherboard.

I will buzz out the cable in case that’s at fault. I’ve already checked the power connection to the drive and that’s fine (light on the actual drive lights up for a few seconds when you power it up.

I do have a Gotek drive on my BBC Master and I’m wondering if I can use that as a check. I’m not sure if there are any firmware differences between Gotek drives for different machines or not.

[stephen_usher]

The Gotek with the normal FlashFloppy will work fine. Just a Shugart defaults and use a raw disk image.

[Slartibartfast]

Ok, tried the Gotek (plus the Sony) and neither are recognised by the Atari ST so it looks like there is an issue somewhere on the ST.

First job will be to check the ribbon connector for continuity. Even if it checks out ok, I think I may desolder it from the board and replace it with a 34 pin header so that I can add a Gotek or 1.44 floppy in the future as the existing ribbon cable is rather short.

I've also ordered up a diagnostic cartridge so hopefully that may help shed some light on things. I guess if the ribbon checks out then the floppy controller will be the next thing to check. I may have a spare as I think it's the same chip as used in my BBC B.

Looks like fixing this machine is proving to be a learning experience on many levels.

[rubber_jonnie]

Ok, tried the Gotek (plus the Sony) and neither are recognised by the Atari ST so it looks like there is an issue somewhere on the ST.

First job will be to check the ribbon connector for continuity. Even if it checks out ok, I think I may desolder it from the board and replace it with a 34 pin header so that I can add a Gotek or 1.44 floppy in the future as the existing ribbon cable is rather short.

I've also ordered up a diagnostic cartridge so hopefully that may help shed some light on things. I guess if the ribbon checks out then the floppy controller will be the next thing to check. I may have a spare as I think it's the same chip as used in my BBC B.

Looks like fixing this machine is proving to be a learning experience on many levels.

Did you set the Gotek to be S0? It needs to be for the ST, plus it also needs the cable to be upside down, the red or black stripe on the cable needs to be near the Gotek power connector, you'll usually see a '2' that indicates the low pin numbers on the Gotek silkscreen.

Well done on getting the machine up and running :)

[Slartibartfast]

Yes, I had set the drive to S0 and also flipped the ribbon cable.

Given that I have not managed to get the original drive, the Sony 1.44 or the Gotek working leads me to think there must be a hardware fault with the machine itself. I’m hoping it’s the ribbon cable as that’s the easiest to fix (apart from desoldering the original from the motherboard).

Hopefully I’ll get the chance to spend some more time on the machine this evening.

[Slartibartfast]

So I’m still struggling to get the machine sorted.

I’ve got a replacement floppy cable and have a pin header on order so that I can replace it. The idea is that my existing cable is quite short anyway and won’t have enough slack to do the twist necessary to install a Gotek drive even if the fault isn’t down to the cable.

I have bought a diagnostics cartridge and this has shown up another issue - quite a number of the keyboard keys don’t work as I cannot select some tests - K for keyboard for instance. Not sure if this is due to a decoding issue or just duff keys but that’s another job on my list. The cartridge didn’t show up any floppy errors when I managed to run the Z test which does a number of things including the floppy I believe.

I then created some 1.04 ROMs and installed them. The splash screen confirms that the machine cannot see a floppy drive but and it booted fine to the desktop but the diagnostic cartridge showed a checksum error on a couple of the ROMs. I used the customised version posted earlier in this thread so is the fact that they are modified the reason why the test failed? The original 1.02 ROMs are fine.

[exxos]

You can select tests via the serial console from A PC for example. You don't necessarily have to use the Atari keyboard.

Not sure what you are referring to as a splash screen for TOS 104. As it does not have one. TOS206 has is the Atari logo pop-up, which cannot run on a stock machine without additional upgrades anyway.

[Slartibartfast]

It’s the version uploaded by rubber-jonnie. After the white screen it the n shows a couple of lines of text TOS version, whether the floppy is connected and the amount of RAM. After a few seconds it drops into the desktop.

[stephen_usher]

That sounds like a custom ROM. The checksums won’t match the ones the diag cart expects.

As for the keyboard issue, that will be the keyboard itself as the connection between the computer and the keyboard is a type of serial port which will either work or not at all.

[exxos]

It’s the version uploaded by rubber-jonnie. After the white screen it the n shows a couple of lines of text TOS version, whether the floppy is connected and the amount of RAM. After a few seconds it drops into the desktop.

That sounds like the one Putnik did me a while ago. It was a custom one he did. Indeed it will not checksum correctly.