>from the help line
>Are there any concerns with a user BASIC program using/modifying the FIOPIN,
DIR, MASK, SET or CLR registers on the MITE or PRO? I haven't seen any
problems, but was wondering if the compiler or firmware assumes 'no background
changes please'?
The BASIC firmware normally sets all FIOs as inputs on reset, with the exception
of RXD0 and TXD0 which are set to those functions for debug.
Also ADs are set to that function on the ARMmite, ARMmitePRO and SuperPRO.
A DIR command will set the PINSEL function back to FIO on the AD pins, and set
the FIO0DIR bit.
The firmware only changes the bits associated with the command, meaning that the
original value is masked with 0 in the appropriate bits and then or'd with the
desired bits (see the last post for an example).