Experiments with eco32-30-port-6
Experiment 1: "Crossed" echo with two terminals, polled
This program repeatedly polls the receivers of the two serial lines
and copies every byte received by the receiver of a specific serial
line to the transmitter of the other serial line.
c0000000: ldhi $8,f0300000
c0000004: ldw $9,$8,0
c0000008: and $9,$9,1
c000000c: beq $9,$0,c0000024
c0000010: ldw $10,$8,4
c0000014: ldw $9,$8,1008
c0000018: and $9,$9,1
c000001c: beq $9,$0,c0000014
c0000020: stw $10,$8,100c
c0000024: ldw $9,$8,1000
c0000028: and $9,$9,1
c000002c: beq $9,$0,c0000004
c0000030: ldw $10,$8,1004
c0000034: ldw $9,$8,8
c0000038: and $9,$9,1
c000003c: beq $9,$0,c0000034
c0000040: stw $10,$8,c
c0000044: j c0000004