about Java IO-interface

Java can deal with mouse, screen, sound card, ...

But from the Java Virtual Machine Specifications, those byte codes
instructions, there do not seem to me instructions to deal with such a
variety of IO chips (video chip, sound chip, ....)

How is it possible for Java to do it ???

You're right - Java is generic enough (write once, run anywhere) that it
does not support specific I/O chips. The only I/O it supports directly
is console I/O and disk I/O. However, external programs (including C and
C++) can be called via the Runtime class.