Crumb wrote:
What is clear is that Buster6/7 don't have DMA support and are slower.
Zorro III DMA. And that only stops you from using a Fastlane or an A4091. Which have issues in a buster rev9 A4000 also.
For the record, my A4000 had a rev9 buster, but was upgraded to a rev11 (re-soldered, as it wasn't socketed). My A3000 has a rev11, but I've never needed to upgrade the ramsey and DMAC chips. It's worked well with the old PP&S Mercury and now CSMK2 as well as the A4091.