Memory expansion

[Tumbleweed]

Hi all,

Is it possible to use more than one memory board in a A4000D?

I have two Commodore A2058's and one Microbotics 8up ram board. One A2058 has 8 meg, the other has 4 meg and the Microbotics board has 2 meg. The Amiga has 2 meg chip and 6 meg fast.

Can I plug in the two A2058's and the Microbotics board to give me 2 meg chip and 20 meg fast?

[countzero]

it depends on if they're zorro 2 or zorro 3. You can't have more than 8 mb on a combination of zorro 2 boards. for zorro 3 boards, there is no such limit (well, there is, but at about 1.5 gb, you'll never hit it in your lifetime)

[banzai]

You can plug 'em all in, but you'll only see 8M. This is because those are all Zorro-II boards, which map into the 8M address range. So, I'd just pop the fully populated one (if the 8-UP! is the SIMM version, that should use less power, otherwise it doesn't matter) in there and sell or use the others in another machine.

If you have a Zorro-III memory board, this will work, as you'll have lots of space for mapping.

And how the hell do you wind up with 6M Fast? If you use 1M SIMMs in the A4K, you'll have 4M max, and if you use 4M SIMMs, then you'll get 4, 8, 12, or 16M. A fully loaded A4k will show 18M total, 2M Chip, 16M Fast (32-bit). The Z2 boards will show up as 1-8M 16-bit Fast. So, the only way is to have the 2M Chip SIMM, a single 4M 32-bit Fast SIMM, and 2M of 16-bit Fast on a Z2 card. The top menu bar would read it as 2M Chip and 6M Fast. Use Sysinfo to get the real picture of what you actually have in there.

banzai

[alexh]

Answer = No.

Commodore A2058 = Zorro II
Microbotics 8-Up! = Zorro II

As has already been said, there is only 8Mbytes in the Zorro II address space shared between however many cards you have.

Again, as has already been said you can have 2+16 Mbytes on your motherboard and 8 Mbytes on a Zorro II card giving you:

2 Mbytes Chip + 24 Mbytes Fast

countzero wrote:
for zorro 3 boards, there is no such limit (well, there is, but at about 1.5 gb, you'll never hit it in your lifetime)

Theoretically yes, but there was a post recently of some nutter who had 3 or more DKB3128 Zorro 3 cards and found they did not 100% work together, due bug in Commodore's expansion.library.

[gertsy]

Yes as long as you plug the 2nd one into a different Amiga 4000 you will be able to address all the memory.  

Sorry time for bed me thinks... :roll: