     1 000000           ; > ECHO tests console by echoing characters
     2 000000           ;   Uses polling to check UART is free
     3 000000           ;
     4 000000                   ORG     O1000
     5 001000 033727    GET:    BIT     @#O177560,#200  ; test RCSR - bit7 set=char rec'd
     5 001002 177560    
     5 001004 000310    
     6 001006 001774            BEQ     GET
     7 001010 013701            MOV     @#O177562,R1    ; get character
     7 001012 177562    
     8 001014 033727    SND:    BIT     @#O177564,#200  ; test TCSR - bit7 set=ready
     8 001016 177564    
     8 001020 000310    
     9 001022 001774            BEQ     SND
    10 001024 010137            MOV     R1,@#O177566    ; send character
    10 001026 177566    
    11 001030 000763            BR      GET             ; repeat continuously
