' A simple dumb terminal to demo the Digimatic RS-232C interface
   ' This code is public domain software.
  
   CLS
   OPEN "com1:1200,n,8,1,cd0,cs0,ds0,op0,rs,tb2048" FOR RANDOM AS #1
   RXPENDING = 0

   COM(1) ON       'Enable event trapping on port 1.
   ON COM(1) GOSUB ComHandler
 
   b$ = ""

MAINLP:

   DO
      a$ = INKEY$
   LOOP WHILE a$ = "" AND RXPENDING = 0
   IF RXPENDING = 1 THEN
       INPUT #1, x$
       COLOR 7: PRINT x$
       RXPENDING = 0
       COM(1) ON
   END IF
   COLOR 15: PRINT a$;
   b$ = b$ + a$
   IF a$ = CHR$(13) THEN PRINT #1, b$; : b$ = ""
   GOTO MAINLP
  
   COM(1) OFF
   END

ComHandler:
   IF RXPENDING = 1 THEN RETURN
   RXPENDING = 1
   COM(1) OFF
   RETURN