        .PROC   DTRON,0 
        .PRIVATE RETADDR

TPORT   .EQU    0C0H            ;UART CONTROL PORT
RPORT   .EQU    TPORT+2;        ;TIMER PORT
CPORT   .EQU    TPORT+3         ;MODEM CONTROL
UART    .EQU    5CH             ;8BITS, NO PARITY, 2 STOP BITS
TODTR3  .EQU    07FH            ;NORMAL OP, 300 BAUD
TRATE   .EQU    250             ;TIMER RATE
TMPUL   .EQU    80H             ;TIMER MASK

        POP     HL
        LD      (RETADDR),HL
        LD      A,TODTR3        ;SET DTR ON
        OUT     (CPORT),A
        LD      A,TRATE
        OUT     (RPORT),A
TIMES:  IN      A,(RPORT)       ; DELAY .1 SECONDS
        AND     TMPUL
        JP      Z,TIMES
TIMEE:  IN      A,(RPORT)
        AND     TMPUL
        JP      NZ,TIMEE
        LD      A,UART          ;SET UART TO NORMAL (SH AND RI OFF)
        OUT     (TPORT),A
        LD      HL,(RETADDR)
        JP      (HL)
        .END

