Excellent so they are active low with pullups
Can I make a sugestion if you are going to have many rom calls (sorry you already know or are indeed doing this
) but use a scheme where the location called will remain the same across firmware upgrades so something like a jump table
org some_fixed_location
JSRead JP Real_jsread
routine1 JP real_routine1
routine2 JP real_routine2
That way if the real_ addresses move, if people are using the official jump table address then they won't have hastles with later software versions.
The other way of course is a single dispatcher routine with a function code in one of the registers similar to OSBYTE/OSWORD on the Beeb, or INT calls on the PC
Cheers.
Phill.