This question is specifically aimed to the Amiga hardware.
Let's assume a floppy track is read via DMA using sync word to trigger the start.
Let's also assume the track contains the sync word multiple times (e.g. 3 times).
I assume I will have 3 random ways to read the track depending on what sync word comes first under the head.
But then what happens to the DMA?
- It ignores the other 2 sync words and just completes respecting the DMA size
- it stops early confused by the unexpected sync words
- any other behavior
I expect 1) as the answer but I have not the time to setup the test. Maybe someone already knows the answer or has a handy dev environment where he can test this.
Answer: the right answer is 1
Credit to @pndc for pointing out that AmigaDOS specs say each sector starts with 2 sync words. This makes sense since it is faster to start transfer from the wrong sector and then fix this in RAM than wait a full disk revolution for the start of the track. It is well described here