Anders Magnusson <ragge@ludd.luth.se> wrote:
> It would be simple to just add mmap() support to /dev/mem, but then you
> must keep track of what you access yourself (wrong address will crash
> the machine :-)

Actually, for the device I want to experiment with, the mmap() isn't
really necessary.  If I can do 8 and 16 bit qbus I/O through reads and
writes to /dev/mem, that would be fine.  (Or do all /dev/mem accesses turn
into byte accesses?)

But I still have no idea where in /dev/mem to find the I/O space.  It
doesn't seem to be at octal 17 760 000 (hex 3fe000); that looks like memory.
(Not surprising since the machine has 48M of RAM.)

Thanks!
Eric