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?

[omnicron10]

It will not autoconfig more than the 512kb of chipram like an a501.  Some of those trapdoor would do another 512 autoconfig but most require the ram to be added to the system via a command like adram.  Almost all of them did not work with A500+ if you are trying to get the 2mb of chip ram via the motherboard and trapdoor slot.

[Oldsmobile_Mike]

^ What he said.  Also, hard to tell from the picture, is that dust in the upper-right corner or is the battery leaking?

[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.

[Acill]

The only way I know of to increase the chip RAM on A500's are with an Agnus mod like the Mega Chip. I dont know anything about the 500+ systems though. We didnt get them here in the US as far as I know.

[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?