Unknown A500 2MB RAM upgrade

[jltursan]

I've lying around a, suposedly, A500 2MB RAM upgrade. The PCB seems built by an unknown brand "BS" (it's the only mark in the PCB).
It has 16 1MBx1 M5M41000 ICs, a battery clock, on/off switch and the usual Gary adapter.
I've never been able to make it work. Recently I've been able to sucessfully plug it in my A500+ and partially worked as a 512MB chip upgrade (?).

Has anyone idea of what it could need to work as a full 2MB upgrade?

[jltursan]

Finally got it working as expected in one of my A500. I just needed to undo the chip ram mod (all of them have it) and voila!, the card is configured as 2MB slow/fast/ranger/whatever mem. A pity chip ram remains unchanged...

In the A500+ seems there's no easy way to get it to work, I would expected (in my wildest dreams) that 1MB gets automagically used as chip and the other 1MB as fast ram .
It's definitely my target machine to upgrade.

@omnicron10: is there a way to achieve the above using adram command?

@Oldsmobile_Mike: No, luckily is only the PCB brighting. The PCB is in very good shape and the battery has only a slighty debris, the pad is still shiny and clean. I'll replace it soon just in case.

[jltursan]

1MB chip is enough for me ;-); but I hate thinking in the other memory being wasted. I need to find info about the autoconfig features of the trapdoor slot and how the RAM is configured.
Can't be remapped as fast RAM using tools like the aforementioned addram or mergemem or such?