but read what David Hayne tells us about it.
Which is not the whole story, I'm afraid. We had one customer with DMA problems on Buster 11, and during development of the ZorRAM it turned out that an (up to now unknown) Buster 11 bug exists.
This bug will hit if DMA on Zorro III is used and heavy load on Zorro III exists. This situation is likely in systems with no CPU card RAM and Zorro III RAM, as well as one (allowed) Zorro III busmaster in action (like the DENEB). It was not found AFAIK up to now as heavy load on Zorro III was not likely and only few DMA cards are available (Fastlane Z3 and A4091).
This is - to emphasize it - not a problem of DENEB DMA operation, but the Buster DMA arbiter itself, which partially locks up.
A new firmware for DENEB is under test - it recognizes this lockup and will take appropriate action to "unlock" the Buster11 arbiter again.
First tests are promising.
On Buster 11 you can only operate *one* Zorro III busmaster, and as long as this is a DENEB you have no problems, as you may use PIO instead DMA, or take the new firmware with a fix.
With Fastlane Z3 or A4091 you may have problems as they are not capable of fixing this bug.
Michael
