***************************************************************
*                                                             *
*      Module Name: WAITBUSY.LIB         Rev. 1.00            *
*      Function: Wait until the busy     Last rev. 06 May 85  *
*         flag is lowered.               By: glh/w6bsk        *
*                                                             *
***************************************************************


cmdreg    equ       0e3fch    ; 1791 command port

notbsy:
          mvi  c,10           ; Preset counter

wait1:
          lxi  h,cmdreg       ; Point to command port of
          mov  a,m            ; 1791 and get a status byte.
          rar                 ; Test busy flag - if not up,
          jnc  timeot         ; wait for it to come up for 
                              ; short period.
wait2:
          mov  a,m            ; Get status byte and test for
          rar                 ; busy flag up. Loop until it
          jc   wait2          ; comes down again.
          ret                 ; 1791 idle, go home.

timeot:   dcr  c              ; Don't look for flag to come up
          jnz  wait1          ; forever. If no busy flag by
          ret                 ; ten tries, is not coming up.