Atari 1040 STFM Mod from around 1990 (not working, link to german forum, lot's of photos, text in german)

[kolli]

Hi,

my 1040 STFM was modded by a friend in the early 90ies: Lighthouse Tower case, AT Speed, Autoswitch Overscan, HD floppy, RTC and RAM expansion up to 3 MB. The machine doesn't work after some 20 years in the attic, so I took it apart and made some photos. You can find them in a thread in the german language forum at atari-home.de. Sorry, too much text for me to translate in english!

Follow this URl to view it: http://forum.atari-home.de/index.php?topic=13297.0

One photo to make you curious



Technically I am not very sophisticated, but I could try to answer questions about it, if you have some. But I really can't tell you anything about the RAM expansion. Seems to be based on an article in german "ST computer" magazine.

At this moment the diagnosis is "Doesn't work". Next try will be connecting a ATX PSU, when I can afford some time for that. I will report, when I find out something new.

Bye,
Kolli

[exxos]

That will be a nightmare to fault find, whats the board over the CPU ?

[spiny]

is that a mod for three floppy drives ?

[prog99]

That will be a nightmare to fault find, whats the board over the CPU ?

It's an At-speed (286 daughter board)

[umberto1st]

Nightmare debug

[kolli]

is that a mod for three floppy drives ?

It's a "multiboard", which was sold with that Lighthouse tower case. 3 floppy drives could be connected, with 2 of them switchable. In my system only 2 where connected, a HD drive as floppy A and the original atari 720 k drive as floppy B.

[vhenares]

I would simplify the computer. I removed all extensions and tested update to update. If all ok, I add an upgrade, until I find the bug.
I would remove the AT plate as a first step.

[siriushardware]

Actually, I would suggest not touching anything until the operation of the power supply (or not) has been verified.

If it was put away working then, as horrible as it looks, everything should still be correct. I would focus on verifying the operation of the power supply / repairing or replacing it if it is not working, first, before trying to undo any mods.

[kolli]

Actually, I would suggest not touching anything until the operation of the power supply (or not) has been verified.

If it was put away working then, as horrible as it looks, everything should still be correct. I would focus on verifying the operation of the power supply / repairing or replacing it if it is not working, first, before trying to undo any mods.

That is exactly the plan! Before changing anything I will try powering it with an ATX PSU. But that needs some time I don't have and some tools and stuff I just ordered today. Be patient.

Bye,
Kolli

[spiny]

is that a mod for three floppy drives ?

It's a "multiboard", which was sold with that Lighthouse tower case. 3 floppy drives could be connected, with 2 of them switchable. In my system only 2 where connected, a HD drive as floppy A and the original atari 720 k drive as floppy B.

cool

[kolli]

cool

Back in the days I also thought so. Today I think, less modification would have been better and I never needed more than the A drive. We kept the 720 K drive as B, because I thought the HD drive would be problematic with games. Today I know I never played (colour) games again after the mod. Only Bolo, Esprit and Oxyd. Instead I "played" with Gemini, MinT, ka9q, Hermes uucp and so on...

I am still not much interested in gaming. Just want to get an Atari with the typical applications and a nice Gemini Desktop up and running.

[catmando]

Was it using an ATX psu previously or did it have an original atari one?

Someone else on here tried to use an ATX psu to debug a Falcon and ended up frying their machine. Adding an ATX psu if it didn't already have one adds another problem before you've even started.

[siriushardware]

Catmando, what makes you say that?

There's no reason why a correctly connected ATX PSU should damage an ST.. the only caveat being that the ST needs to be checked for shorts on the 12V-Gnd and 5V-Gnd paths -before- connection, because ATX PSUs can source so much current that they would probably try to maintain their output into a near dead short, especially on the 5V rail.

Doing pre-connection checks and if possible Inserting inline fuses into the +12V and +5V feeds from the ATX PSU would address that potential problem.

[catmando]

Catmando, what makes you say that?

There's no reason why a correctly connected ATX PSU should damage an ST.. the only caveat being that the ST needs to be checked for shorts on the 12V-Gnd and 5V-Gnd paths -before- connection, because ATX PSUs can source so much current that they would probably try to maintain their output into a near dead short, especially on the 5V rail.

Doing pre-connection checks and if possible Inserting inline fuses into the +12V and +5V feeds from the ATX PSU would address that potential problem.

Yes there's no reason why an ATX power supply can't be made to work, but my point is it just adds another ingredient to the cake when you don't know if the recipe you have works in the first place.

[kolli]

Yes there's no reason why an ATX power supply can't be made to work, but my point is it just adds another ingredient to the cake when you don't know if the recipe you have works in the first place.

The recipe IS working! The beast is alive!

After connecting the ATX PSU there was no sign of life. I found out that the switch to select monochrome or color monitor was dead. Cut it off, connected the wires. Again nothing. Thought that the switch to choose TOS 1.02 or 1.04 could also be bad. Cut it off, connected the wires and TADA!



Connected the HD floppy drive and the external PC keyboard adapter. It was able to load sysinfo from disk.



Further tests have to be done, but this is starting great!