The final step is to write the disk write routine.
In the CP/M-80 with blocking/deblocking code, the disk write routine is a "writehst" routine.
Basically, the same code as the disk read routine can be used. The only difference is the command number.
The biggest problem is how to write commands to the DMA? Without the documentation ("X1 on the exam"), it would have been impossible to implement on our own. Below is the DMA command chain used for the SORD M68 disk write routine.
It will not work correctly without the two commands (0CFH,05H) on the second line from the bottom. This section is firmly in the "X1 on the exam". Also, I found "Z80DMA Command Code Generator Z80DMA Command Generator 2019.6.19" very useful on the net. The trick to using this service is to "click the buttons that are marked by default properly". In my case, otherwise I did not get 0CFH,05H. This is a point to get stuck on.
Translated with www.DeepL.com/Translator (free version)
In addition, the DMA command chain for reading floppy disks is noted.
This completes the porting of the CP/M-80 to the SORD M68. Thank you for reading.