520 STE 2 bombs issue

[oissery77]

Hi everybody,

I acquired a 520 STE Tos 1.62 which worked perfectly and I bought an IDE card that is installed on the CPU socket.
I've made two errors on installation :
1 / I used a needle to facilitate insertion and I damaged the CPU socket.
2 / I connected the interrupt wire leading from the card to the wrong pin of the ACSI port (Harddrive) : connected in pin 1 instead of pin 10

The result: on the GEM as soon as I'm trying to go to the menu or drive A: 2 bombs are quickly displayed and GEM reboots.

The retailer card kindly proposed to repair my CM with installing a funky socket of Exxos with a tos 2.06. The repair was successful but not completely because I have sometimes two bombs eg. in medium resolution and in some specific Ste games like wings of death (2 bombs each time just at the beginning of the game). With other old games like rick dangerous it works.

Summary of my tests:
-other CPU: same behavior
-test of the 4MB RAM with testram: no mistakes. I swapped the SIMMS and tested with 2MB: not better
- I removed/replaced all the chips socketed chips : not better
- Disk formatting of 82 tracks with fastcopy3: ok

Maybe the chip WD1772 is involved or the Blitter?
If one of you has an idea that would be great!
Thank you!

[veegee]

Hi,

2 bombs is a bus error asserted by the GLUE or the CPU - I would suggest it might be TOS2.06 which you can check by using a software loader to put 1.62 into RAM.

Alternatively you could have damaged one of the chips connected to line 1 of the ACSI port - either the buffer (U302) or the DMA chip.

Wouldn't have thought it was a Blitter problem and if the drive formats a disk without a problem I would suggest the 1772 is also good (unlikely to have been damaged as it isn't connected to pin 1 of the ACSI as I can see).

Check all the PLCC contacts are making properly on the CPU and the GLU - I had a bus error that was caused by a slightly out of shape pin on the GLUE socket.

[oissery77]

Many thanks veegee for your answer. So the issue may not be the 1772 or the blitter.

For the TOS : I own physically the two TOS and i switched from one to another : same issue.

The 74LSxx chips have been tested by my reseller and they are good but i don't know for the DMA chip. The DMA chip is not on socket.

Last point about the PLCC contacts: for the GLU it is not socketed but it can be the case for the CPU because the IDE interface moves the pin when inserted. To you know how to test it ? with a multimeter maybe but the space is really tiny to do it

[veegee]

Only way to be sure is to thoroughly clean the contacts and make sure they are all straight and the chip fits tight.

You can check the continuity with the multimeter - get hold of the schematic and trace each CPU pin out - you show see 0 or very close to 0 ohms resistance anything more means a potential short or bad contact.

[oissery77]

Ok thanks a lot. i will do that, just need to find the Cpu pinout.

[dlfrsilver]

and change the PSU's capacitors if it is not already done

[oissery77]

and change the PSU's capacitors if it is not already done

thanks i will do that.


I will have soon an other STE. I will swap the PSU for the test too.

[veegee]

Ok thanks a lot. i will do that, just need to find the Cpu pinout.

grab the schematic from here :-

http://dev-docs.atariforge.org/files/ST ... 3-1989.pdf

[oissery77]

Thanks veegee now I need to understand it! I will made some tests and I will made a feedback.

[oissery77]

So after some checks, i noticed that the blitter socket had 2 pins was not aligned with the others maybe due to the transport of my CM. So i have pushed the 2 corresponding pins on the blitter and it worked! not more 2 bombs on the screen

But i noticed other little problems now :
- when i launch a game on my CF like cadaver, Peter Putnik has added a high resolution capture of the box game : the screen is totally corrupted (on steem it's ok) after that the game runs normally.
- the game "obsession" is continually flickering since the screen of the flipper choice
- the CPU is really hot (for this part i will compare with an other STE soon)
- one pin of the shiffer socket was pulled out, i hand it straight in the socket . Can it be a consequence of taking off the shiffter?

So it's really better but not perfect...

[oissery77]

Another interesting test:
If i unplug the IDE interface, my STE is working well not glitch at all for exemple "obsession" is working great with the floppies
If i plug the IDE interfafce and i run "obsession" from the same floppies : i have glitches !

I noticed that the IDE interface can be very easily unplugged for the socket. So maybe it's a bad contact with the IDE interface.
FYI : screenshots of the inteface:
http://www.yaronet.com/topics/185190-in ... /3#post-65

[redhawk668]

I have the same IDE controller in my STE, the issues you are describing are exactly what I am experiencing too. Most of the games run normally, but the hires titlescreens look totally corrupted. For example, games like Lethal Xcess, Giana Sisters run like crap. All flickering, glitches, etc. If I take it out, everything runs normally. For the rest my STE runs great and IDE is running reliable for the most part. I think the problem is with this IDE controller, if I'm able, I will order a controller from Alan Hourihane and take this one out. I think that will solve the problems. First, I will try a SD to IDE converter, should arrive shortly. I am now using a passive CF to IDE converter. It might solve the problems, I don't know.

[oissery77]

Thanks for your return, in fact it was my ide interface. I've changed it and it works but i will test the games you have listed in your post anyway.

[redhawk668]

You replaced the controllercard? Did you replace it with a controller of the same design? Do the hires titlescreens look normally now? If everything is running like it should from the CF cards, then I think I might have a bad card too.

[oissery77]

Yes I replace it from the same kind of ide interface and the hired picture are correctly displayed.

[redhawk668]

Did you buy a new one? I've now tested a real 2,5" harddisk and still same issues. Does your IDE card stay properly in the PLCC socket?

[oissery77]

I have contacted my seller to replace the old one.
Maybe you have an issue with you cpu socket, check visually if a pin is damaged, same check to do with every socket chip i think. One other good test is to check your mass storage support on another Ste.

[redhawk668]

I've bought a new one, but will check my socket first.

[redhawk668]

I am now testing a SD to IDE adapter instead of CF to IDE, but the results are promising. Highres scans look normal now, Lethal XCess and Giana Sisters actually playable.

[oissery77]

I am now testing a SD to IDE adapter instead of CF to IDE, but the results are promising. Highres scans look normal now, Lethal XCess and Giana Sisters actually playable.

Interesting ! Can you tell me what kind of SD to IDE adapter you used? Is the SD card direcly working (no need to set a jumper to slave) ?

[redhawk668]

I am using this SD to IDE adapter:

http://www.delock.com/produkte/F_659_ID ... kmale.html

It is being identified as a Sintechi SD to CF. I am using it with a cheap 2 GB sdcard. I did not have to set any jumpers, working out of the box.

How did you secure your IDE controller card in the PLCC socket?

[oissery77]

Thanks for the info about the SD adapter maybe i will give a try with it.

For the IDE controller, i schedule to add hot glue because the interface can be unplugged to easily. Then on top il will add an electronic scotch to protect it.

[redhawk668]

Ok, that's what I thought too. I had to cut the RF shielding to fit it inside.