Zorro2 memory in Zorro3

[lillPiP]

Is it possible to use multiple Zorro2-memorycards in the Zorro3 on my Amiga4000 or is it only possible to use one?

[mboehmer_e3b]

Is it possible to use multiple Zorro2-memorycards in the Zorro3 on my Amiga4000 or is it only possible to use one?

AFAIK there is no limitation, except that Zorro II cards will go into a limited address space. Zorro II address space is limited to 8MB between 0x200000 and 0xa00000 on Zorro III machines.

Zorro cards will always be configured to their natural boundaries, i.e. 2MB cards will always be located on 2MB boundaries.

So you can put two 4MB cards in, or one 8MB card, but not more. If other Zorro II memory cards are in (like a Picasso II), then the address space will be even more limited.

Zorro III cards will be out of the Zorro II address space and won't use it, so no need to worry.

Please note that Zorro II memory cards are slow, and sometimes cause problems in Zorro III machines (if the design is not done correctly).

Michael

[Argus]

You'd be limited to the max 8MB of available zorro II memory space.  Stay away from old cards with sloooow dip chips on them (100ns or faster is absolute minimum).  Even then, the Z2 memory is only 16 bits wide so it's a big bottleneck to the processor.  Better to max out your m/b ram or better yet, get processor local 32 bit ram on an accelerator slot card.

[motrucker]

The 16 bit bottleneck is the biggest point. Stay away from these old cards on a Z3 system!

[KThunder]

if i remeber correctly zorroIII cards can be up to 1gb in size and full bus speed. its too bad noone made any besides commodore. nowadays 1gig of ram doesnt cost very much

[alexh]

Too bad no-one made any besides commodore

What are you talking about? Most ZIII boards were made by people other than commodore! The largest dedicated RAM board was the DKB3128 by Dean Brown which takes 128Mbyte, the largest ZIII memory device was the Fastlane SCSI card with the last version supporting 256Mbytes.