CF card not working with DMA enabled.....

[Sandman]

Hi,

I have just added a CF-to-IDE to IDE-to-SCSI setup on my A3000.  Works fine when DMA is disabled on the CF-to-IDE adapter but machine locks up when DMA 'IS' enabled.

Any ideas anyone??

[mongo]

Hi,

I have just added a CF-to-IDE to IDE-to-SCSI setup on my A3000.  Works fine when DMA is disabled on the CF-to-IDE adapter but machine locks up when DMA 'IS' enabled.

Any ideas anyone??

Don't use DMA.

[Damion]

I have the opposite problem (system won't boot with the DMA jumper disabled) but my understanding is that it really shouldn't matter.

One idea is to download and run RSCP, it should give you an idea whether or not DMA is working. PIO would be really slow, while using a lot of CPU.

[Zac67]

Actually it doesn't matter at all whether DMA mode is used on the IDE side or not. PIO limits you to 16 MB/s which is most probably faster than your SCSI. Your local SCSI has its own DMA scheme, totally independent of IDE.

PS: Trying to use DMA with a CF card not supporting it probably causes the lockup.

[Damion]

Actually it doesn't matter at all whether DMA mode is used on the IDE side or not. PIO limits you to 16 MB/s which is most probably faster than your SCSI. Your local SCSI has its own DMA scheme, totally independent of IDE.

Thanks for clarifying, makes sense that PIO/DMA on the IDE side won't affect things on the Amiga end.

PS: Trying to use DMA with a CF card not supporting it probably causes the lockup.

I've certainly found that to be the case here, also some DMA capable CF cards don't work on CF adapters not supporting DMA (or without the DMA jumper set in the case of those adapters).