[rnol]

I would like to know if there are any classes available for control of the serial or parallel ports -- or better yet memory locations as would be requird to access Digital contol IO cards.

Thanks

[jan_vrany]

I don't know any classes for that - or at least any classes in publicly available
St/X version. On UNIX you can communicate directly via /dev/ttyS0 or similar. Unfortunately,
there is no generic ioctl() interface. For accessing specific memory locations, it might be possible to use ExternalBytes class with address set to the begining of the given memory location.

Another solution is to write a tiny C library and call that library using FFI.

[rnol]

Thanks
I will explore the FFI option.

[jan_vrany]

OK. Please note, that FFI in 5.4.2 is broken (when C function returns a pointer, the highest bit lost and
thus the returned value becomes unusable. 5.3.6 release is perfectly OK.
(this bug is fixed in ExternalBytes.st r1.72)