In a message to Anthony May about amazing facts!, Rod Speed said:

RS> It depends. Its actually better to be able to DMA directly into
RS> the whole of the ram on the system. Thats much more efficient.
RS> The main problem is that the ISA bus just doesnt have the
RS> address lines to allow that.

Yeah, I realize that, but considering that's been the way for video
cards until quite recently, it can't be too bad.  Obviously, if you
have the money/choice, a EISA/MCA/VLB bus would be the way to go to
aviod the problem all together.  At least Adaptec have provided a
mechanism that aviods the problem.  Do any of the other scsi ha
cards take this approach, or are they stuck with <16Mb ram systems?

'tnt, Anthony.