DEFINE (CHARACTER,BYTE)
# TEST4
   BYTE STR1(20), STR2(20), STR3(20), STR4(30), STR5(20)
   INTEGER SCOPY, I, J, ERROR, LEN, N, SLEN,ISLEN,SREPT
   INTEGER SSWAP, SMIDV, SINSRT, STRGET
   STRING FILL "?+"
#
   REPEAT [
      WRITE (5,1)
      1 FORMAT ("$STR1>")
      IF (STRGET(5,STR5,19) > 0)
         JUNK=SCOPY(STR5,STR1,19,ERROR)
      2 FORMAT (Q,20A1)
      4 FORMAT (I4)
      WRITE (5,7)
      7 FORMAT ("$STR2>")
      READ  (5,2,END=100) IQ, STR2
      IQ=MIN0(IQ,19)
      STR2(IQ+1)=0
      WRITE (5,8)
      8 FORMAT ("$STR3>")
      READ  (5,2,END=100) IQ, STR3
      IQ=MIN0(IQ,19)
      STR3(IQ+1)=0
#
      LEN=SSWAP(STR1, STR2, STR3, STR4,29, ERROR)
      ISLEN=SLEN(STR4)
#
      WRITE (5,9) LEN, ISLEN, ERROR, STR4
      9 FORMAT (" LEN=",I3,"  ISLEN=",I3,"  ERROR=",I3,"  STR4=",30A1)
      ]
   100 STOP
   END