As mentioned in the earlier log on the DMA disk driver, I have now written a RBF driver that sleeps during the phase after issuing a read/write command to the IDE disk controller and uses interrupts to wake up for the DMA transfer phase releasing the intervening time for other processes. There is no clash with other processes that want to use the DMA controller because it is only setup for data transfer during the actual data transfer phase, not when the IDE command is issued.

During the debugging I noticed an error stemming from the original driver (which is also updated) in that I tried to check the type of disk before it was defined... The verilog code for the IDE interface board was updated to provide the required interrupt signal and its associated status bit.

Both versions of this RBF driver are uploaded in source form.

Whilst going through the motions of updating the driver I noticed that the Programmer's Manual hints that since OS-9 level 2 version 1.2 (which is covered by the rev. H of the manual) a new SUSPEND state would improve the RBF even further since it does away with the wake up signalling ( section 5.3.2 page 5-11). For an electronic copy of the manual look at my CodeBerg repository under OS-9 documents.

So I have revised my IDE RBF driver using this new feature. So now there are three versions of the IDE RBF driver available. Obviously the latest: myIDEdrv_IRQ_Suspend.asm is the one to go for since it has all the features available that were discussed. The other two work and have been provided for those that would like to see the changes between them.