Cumulus Issues

[Chema]

You can always remove that resistor and see what happens. Maybe the Oric doesn't boot anymore, maybe Cumulus works, maybe nothing. And you might well do something wrong in the process.

So at your own risk...

Edit: need to stop folding the forums. I just checked the Oric schematics and that resistor appears. Don't know why you have it soldered in the bottom side, though. Also don't know if it is the same value.

[metadata]

PHI 2 on my oscilloscope: With and without Cumulus connected.

[peacer]

Hmm.. thanks..

I still hope we'll find a way..

@metadata.. so, what does it mean?

[metadata]

we are trying to find out if there is something wrong with the PHI 2 line.

[peacer]

I see..

[Symoon]

This may sound stupid but I never clearly understood what happened to me, so Peacer:
- do you hear some background sound from the Oric speaker when running your Cumulus ?
- if so did you try moving the Cumulus around, away from the Oric, closer or whatever ?
- did you try letting everything turned on for a while and test it again ?

This is absolutley not scientific or rational or whatever, but as I experienced some instability or stability by having only these changes in mind, who knows. Sometimes by doing things that may sound stupid, we can see the light and find ideas that lead to a solution.

[metadata]

This may sound stupid...

no... it is normal for a 30 years old computer. There are always issues with the capacitors after this long time. Luckly the Oric is not so sensitive to this problems but with the connected cumulus it is maybe. I have seen a lot of strange thing because of defect capacitors.

[peacer]

Hi Symoon.

- do you hear some background sound from the Oric speaker when running your Cumulus ?

Not at all, other than normal process. Just, Sometimes after hang-up during booting, regular "ping" sound is heard probably due to chr$(7) effect. if I wait, the screen regularly changes . Sometimes all the screen is filled with continuously changing characters, dots, colors, blinking lines or pixels randomly -as I can guess- due to flowing data from cumulus and VDU displays random data on the screen while keyboard is completely deaf.. Sometimes a random keypress happens one after another on the screen, cursor keeps on flashing . Sometimes after boot command from cumulus, it acts as if pressing soft-reset key behind the case and just display "Ready" message. So Oric goes in many different "insane" behaviours after each "RESET ORIC" attempt.

- if so did you try moving the Cumulus around, away from the Oric, closer or whatever ?

I tried to use cumulus close and away to oric as much as IDE ribbon let me. No better or worse effect

- did you try letting everything turned on for a while and test it again ?

Yes. I set up the system and let it run while cumulus is attached and waited more than half an hour. During this time, screen continuously changes as I described above. I tried to check and do anything that I could think and struggle for a long time at monday when I received my cumulus and I think it took more than 3 hours long before I gave up..

@metadata : We've tested capacitors located on the circuit of Oric when case is opened to take the pictures that I presented before. They are working fine and it seems that no problem with them either.

[Godzil]

Maybe i'm tired tonight, but I see the resistor on the ULA connecter on pin 17 to pin 34 which are D1 and D6 o_O (I think I'm tired...)

You have one of the recommended reworks (on the top right) the resistor just on "bottom" of the DRAM is not something I already see before... sounds strange...


Metadata, there is a bit more noise on Phi2... I home there is not a problem on the failing Oric... Can you verify that the cumulubus is buffering this signal?

Anyway, I think you Oric miss on of the "official" rework, I will check this tomorrow.

[Chema]

Maybe i'm tired tonight, but I see the resistor on the ULA connecter on pin 17 to pin 34 which are D1 and D6 o_O (I think I'm tired...)

You have one of the recommended reworks (on the top right) the resistor just on "bottom" of the DRAM is not something I already see before... sounds strange...


Metadata, there is a bit more noise on Phi2... I home there is not a problem on the failing Oric... Can you verify that the cumulubus is buffering this signal?

Anyway, I think you Oric miss on of the "official" rework, I will check this tomorrow.

I can't tell... I think you might be looking at the ULA "upside-down", because connecting D1 and D6 does not make sense (?). I overlooked the resistor near the DRAM. It seems to connect condenser C2 (not sure) and Ground, but it is difficult to tell without a polimeter. I'd say the original track has been "cut" to place the resistor. According to the schematics in http://oric.free.fr/IMAGES/oric1-1s.gif C2 is related to the loudspeaker, so maybe this rework is just to improve sound.

I could try to borrow an oscilloscope and measure my Phi2 signal, but I am quite reluctant to do so, because I am clumsy and I am afraid to damage my Oric by making a short circuit or something like that.

[Godzil]

Yes it's clearly does not make sense

I've just finished and tested a tool to calculate the CRC32 of the ROM.

You can find it here:
http://forum.defence-force.org/viewtopi ... 205#p10205

I've only tested it on oricutron 1.1 from OSDK (which crash really frequently on my computer..) can someone try it on a real oric? You should get the same CRC value as in the Fabrice list that Chema post earlier

[peacer]

Just to let you know that, we've removed the claimed resistors and tried again. Removal of One of them lead to loss of screen view. The other one did nothing. But this does not effect cumulus failure either.

Anymore suggestions?

[Godzil]

Screen View?
Which one? The one on the left (near the DRAM chip?)

[peacer]

No, my dad said, resistor near adjustable capacitor.

I also bought 2 different SDHC cards with 4 and 8 gigabytes (Kingston) . They both are recognised by cumulus and all the .dsk images are listed properly but booting with any of them again ended up with hang up

It seems to be a very easy to fix problem. Everythng is normal but I can't use my cumulus, its very upset..

[NightBird]

In your pictures I see one strange connection between a pin in the ULA and ground with a resistor that does not appear in the usual boards.

Hmmm... It looks like the Oric mod 63b for boot reliability. Please see the Oric Service Manual (page 72) @ http://www.48katmos.freeuk.com/projects.htm

I have a question. I do not understand how the Oric is powered with Cumulus. Is the Cumulusbus powering the Oric? Is the original PSU also needed? A new howto will be really appreciated! Thanks!