Super Gold Cards - unrecognised ROM

[RWAP]

Does anyone know why the Super Gold Card sometimes gives 'unrecognised ROM - please contact Miracle Systems' on the start up screen on some QLs, but not others?

I have a JM ROM QL which works fine with another Gold Card and Super Gold Card, but this particular Super Gold Card gives this error on startup.

Oddly on another QL (JS ROM), I needed to remove the 68008 processor for this Super Gold Card

On a third QL (JM ROM) it works fine, despite having to maneouvre it around a bent pin in the QL's expansion bus....

[skagon]

I guess you'd have to compare the ROMs of the Gold or SuperGold cards as well as the ROMs of the QLs. For the QLs I mean, binary comparison. I don't know if it's known to have happened, ROMs with the same version but slightly different code?
Also I know, the JM ROMs weren't exactly new, but maybe, just maybe, that particular card doesn't recognise the ROM.
The Gold card is copying the entire ROM contents onto its own RAM and patching it for changed addresses. Obviously, the patching needs a recognised ROM version, in order to change specific bytes. I don't know if the Gold (and probably the SuperGold) card's ROM is just using the ROM version or doing some sort of checksum on the contents whilst or after copying.
You could always swap ROM chips and see if that makes a difference; i.e. is it the machine that's causing the problem or the ROM?

The thing about removing the 68008 for the card to work, might be as simple as simply getting rid of the power consumption of the '08 or even its load (or maybe noise) on the buses.

I'd get some measurements of voltage levels and noise with and without -- with an oscilloscope -- and see exactly what gets better or worse.

[Mr_Navigator]

Does this mean that once you have sorted the issue, you will be selling a Super Gold Card?

[Mr_Navigator]

Does this mean that once you have sorted the issue, you will be selling a Super Gold Card?

Ha, that will teach me for reading unread posts top down

[skagon]

He is already selling a SuperGold Card.
If I understand correctly, there are two fully working and one sort-of working in total.
First one, £245.

[RWAP]

Yes there are 3 Super Gold Cards in total - there are 2 listed on SellMyRetro at the moment, until I figure out why this one is not playing ball - whether it is my normal test QL, or the Super Gold Card...

[RWAP]

I have managed to get this Super Gold Card working with the QL which was causing problems - oddly I just changed the EPROM on the Super Gold Card (both said v2.49) but there must be some difference

[Dave]

I suspect you may find that simply re-burning the bad EPROM with the image from the good EPROM may solve the problem permanently. The EPROM may have been exposed to UV over a period of years and some of the bits may have just become marginal.