Cumulus Issues

[Chema]

Tested my two Cumuluses today and finally got them working. All the problems were, in the end, related to incompatible SDHCs. Managed to find a working one eventually

Nice to hear this... Could you report the brand and type of SDHCs you found incompatible and those which worked? In the Cumulus thread there is a list that could serve potential Cumulus users to choose a compatible card (or discard an incompatible one before getting mad)

[Steve M]

I finally got round to testing my Cumulus and got it working. Most difficult bit is lining up the little board that goes in the expansion slot. It could do with something that fits better but I guess that would increase cost and so on.

The buttons are a bit small and fiddly but managed to find my way round the menu system eventually and realised the need to reset the Oric for the disk to boot. 4gb card worked and the 8gb which is class 4 (I'll need to check the 4gb again but I think it is a class2.)

Tested 4 Atmoses so far. First three worked OK once I'd properly located the fiddly expansion post connection. But the fourth Atmos seized when it tried to boot the disk. Had a look at the board to see if it was messed with but it looked quite neat with no modifications that I could see. Tested it with the Cumana interface and it worked fine. Curious!

[peacer]

Hope you find the diference between working and non-working boards to solve my cumulus issue..

[Steve M]

Tried some more and got 3 out of 9 not working with Cumulus.

One Atmos didn't boot too well (on it's own), with a scrambled screen but it booted OK with the Cumana interface and loaded a disk OK.
One had 74ls04 replaced with a 74f04 (?) tried swapping it for a different chip. Worked with Cumana but not Cumulus.
Other one had different memory chips - maybe there is a slight incompatibility with some chips???

Will try and look at more later. I want to try and get some of the Atmoses that don't boot (at all) up and running. I need to get an oscilloscope. Keep missing them on Ebay!

[Chema]

Well finding a set of Orics that don't work with Cumulus is indeed a start to spot the problem!

[Godzil]

The memory chip swap could be a problem especially when mixing incompatible CMOS 74HC* and TTL 74LS*/74*, you must use 74HTC* as a replacement for 74LS*/74*

Steve: You are in the UK? (ok Cumbria seems really far from London, but shipping would be inexpensive. If you found a board that have lots of problem with the cumulus, you could lend it to me that I can check what's happen on it..

(By the way, if you found in your "collection" a 16K layout PCB, whatever the working condition, I would be happy if I can acquire it)

[ Metadata: What device do you use to program the E(E)PROM? it is parallel based or USB based? ]

Edit: It seems that 74F* are "standard" bipolar TTL chip, just faster than normal 74LS, cf wikipedia:

74LS – Low-power Schottky. Implemented using the same technology as 74S but with reduced power consumption and switching speed. Typical 10 ns gate delay, a remarkable (for the time) 2 mW dissipation, 4.75–5.25 V.
74F – Fast. Fairchild's version of TI's 74AS. 3.4 ns, 6 mW, 4.5–5.5 V. Introduced in 1978.

The voltage range is a bit larger, and I don't know if they are for input, or output..

[metadata]

[ Metadata: What device do you use to program the E(E)PROM? it is parallel based or USB based? ]

It's USB based. Genius G840.

[Steve M]

The memory chip swap could be a problem especially when mixing incompatible CMOS 74HC* and TTL 74LS*/74*, you must use 74HTC* as a replacement for 74LS*/74*

Steve: You are in the UK? (ok Cumbria seems really far from London, but shipping would be inexpensive. If you found a board that have lots of problem with the cumulus, you could lend it to me that I can check what's happen on it..

Yes I'm in the UK. (At the top where the air is cleaner !) PM me your details and I can try and send something. (Thinks - I need to parcel up some keyboards for Swedish chap - not forgotten!!!)

Most of my Atmoses do not power up nicely with the clean blocks of black and white. I think Fabrice said this only happened with the right memory chips(?) Some boards have the 2600 whilst older boards have the 4164 4264 etc (Is that right - going from memory - ha!!!)
I've not found a consistent pattern so it may be more complicated than chip type.

[Godzil]

[ Metadata: What device do you use to program the E(E)PROM? it is parallel based or USB based? ]

It's USB based. Genius G840.

Nice and no that expensive, are you happy with it?

[Steve M]

Yargh!
I've knocked the jumper off the little board that connects to the expansion port. Should it be over the two pins? I don't recall it being over them both.

(Got Cumulus to work with 2 Oric-1s.)

[Chema]

Speaking from memory now, but I am pretty sure that the jumper was just over one pin. That is, the pins are NOT connected.

[Steve M]

Thanks! What's it for then???

I found my Atmos with most chips in sockets so thought I'd swap some memory chips. They were all 4164 to begin with. Put in two 2600 and Cumulus worked OK. Swapped a couple more for some 4864s and it wouldn't boot the disk. Swapped the 2600 for some 4264 and still no joy. Swapped the 4264 for 4864 and it worked again.
(The 4264 had a bit of solder on the legs so there's a chance the connection wasn't too good, I guess. )

So I think it's proved the memory chips can be a problem when they are not all the same.

[Chema]

You should shortcut this and the one inside the cumulus to use the connector in the middle of the cable instead of the one in the end (at cumulus side)

Not sure of you also have to interchange the connectors in that case. In theory that should be better when the bus signals are poor.

[metadata]

I've knocked the jumper off the little board that connects to the expansion port. Should it be over the two pins? I don't recall it being over them both.

normal the pins are not connected. You can close the jumper and the jumper in the cumulus and then you have to use the black and the grey connector on the IDE-Cable.

btw... i am working on a user manual for the cumulus. That is one thing that i will write in the manual.
If you know what else is important for the manual let me know

[metadata]

[ Metadata: What device do you use to program the E(E)PROM? it is parallel based or USB based? ]

It's USB based. Genius G840.

Nice and no that expensive, are you happy with it?

it's okay. it is a lot better than my parallel one. The software for the parallel one only runs under windowsXP.
The software from the G840 is better but it is also made in china. But it works and if you have to burn more than 1 roms at a time it has a nice feature. You only have to press a button on the programmer to repeat the burnprocess. I burned 50 roms within a few minutes with it.