the resultant character stream from three devices with different rates and individual streams A$1$A$2$A$3$A$4...,$ B$1$B$2$B$3$B$4...,$ and C$1$C$2$C$3$C$4$ using byte I$/$O multiplexer channel might be:

$*$

A$1$A$2$A$3$A$4$B$1$B$2$B$3$C$1$C$2$C$3$A$5$A$6$A$7$A$8,$ and so on

A$1$B$1$C$1$A$2$C$2$A$3$B$2$C$3$A$4,$ and so on$.$