;                    ------------------------------
;                    .  SENDS TTY Output Routine  .
;                    ------------------------------
;
;     SENDBRK is a routine to send a continuous break to an IBM mainframe.
;     The appropriate PASCAL declaration is:
;
;         PROCEDURE SENDBRK; EXTERNAL;  (*to send a break*)
;
;
XDB       .EQU   177526        ; absolute address, transmit data buffer
XSR       .EQU   177524        ; absolute address, transmit status register
;
;
          .PROC  SENDBRK
;
SNDB1:    BIT    #200,@#XSR    ; wait for previous char to complete
          BEQ    SNDB1
;
          MOV    #1,@#XSR      ; transmit continuous break
          MOV    #310,R1       ; wait 200 (=310 octal) milliseconds
SNDB2:    MOV    #124,R0
SNDB3:    SUB    #1,R0
          BNE    SNDB3
          SUB    #1,R1
          BNE    SNDB2
          MOV    #0,@#XSR      ; clear continuous break
;
          RTS    PC            ; and return
;
          .END

