amiga fast ram help

[23703jim]

i have an amiga 3000 desktop it has 2 megs chip ram and 1 meg furnished by zips the other fast ram sockets are mty. since memory zorro type III are practically non existance i bought a zorro II memory board with 8 megs on board zip variety. supra memory 2/4/6/8 card.
the machine recognizes this memory fine. giving me a total of 9 megs (8 on the card and 1 on the motherboard.
i also have a zorro II card with simms on board (30 pin one meg simms with 4 one meg simms installed)
it does not see that card????why?
i know the machine can go up to 16 megs all total with the two cards and one on board only the total would be 13 megs.
please tell me what i am doing wrong???

thanks so much for your past help :-?

[Jeff]

You have only 8 megs of Zorro II memory address space with which to work with. The Supra card already has your machine maxed out.

You will need motherboard zips, the impossible to find Zorro III memory expansion, or an accelerator with a memory expansion option to go further than you are.

Jeff

[Methuselas]

Dump the 8MB ZII card, ASAP, as you will experience SEVERE lag with it installed. I had one in my A3000 for a while and it was actually frakking faster with just the stock 2 megs, than with the 8 Up card.

16 bit ram sucks on a 32 bit bus.

[alenppc]

You should only use Zorro-II ram when absolutely necessary on a 32-bit system as it slows the CPU down to a speed comparable to a 7 mhz 68000 due to the way this memory has to be accessed.

As already mentioned in this thread the Zorro-II bus can only address 8 Mb, and that includes any zorro-II graphic boards you might have installed. This means that for example if you have a Zorro-II gfx card with 4 Megs of ram you have only 4 megs left for other purposes.

Obviously any memory is better than none, but its priority should be the lowest so that it does not get used unless absolutely necessary.