Check OAM Comparator output

[ogamespec]

To me, it looks like the four '2 Bit comparator/subtractor cells' have low_active carry input/output and low_active "OV0..7" sum outputs.
Can you confirm this ?
https://github.com/emu-russia/breaks/blob/master/BreakingNESWiki/imgstore/oam_cmpr.jpg
If this is the case, then to me it looks like the comparator/subtractor output = NOT(V-OB-1)

[ogamespec]

Not confirmed.

The output from the OB goes to the comparator in direct logic.

The output V goes to the comparator in direct logic.

The simulation shows that the comparator performs the operation OV = V - OB.