SETPIN GP1, GP0, COM1
OPEN "COM1:4800" AS #1
'the program loop
'every second it sends "X" then waits for a second.
'then it reads the received 6 characters into a$ and prints them.
do
 print#1,"X"
 pause 1000
 a$=input$(6, #1)
 print a$
 pause 1000
loop

SETPIN GP5, GP4, COM2
OPEN "COM2:4800" AS #2
'the program loop
'this keeps looking for a character in the receive buffer
'if there is a character there then it sends "Gotcha" as a reply
do
 a$ = input$(#1)
 if a$ > "" then
   print#1,"Gotcha"
 endif
loop
loop

do
a$ = input$(#1)
if a$ > "" then
  print#1,"Gotcha"
endif
loop
loop

'terminal program for PicoMite

'open port
SetPin gp1,gp0,com1
Open "COM1:9600,,rec_int" As #1

'transmit loop
Do
 Do
   a$=Inkey$
 Loop While a$=""
 Print #1,a$;
Loop

'receive
Sub rec_int
 b$=Input$(10,#1) 'max 10 characters at once
 Print b$;
End Sub

Open "COM2:9600" as #2 'Open the COM port
DIM MSG$ 'String to hold any one message
DO 'MAIN LOOP HERE
 MSG$="" 'Clear the global message string
 ...
 If LOC(#2) then RXD 'Something has arrived in the serial port buffer
 If MSG$<>"" then Print MSG$ 'Show the message on the terminal screen if there is one to show
 ...
LOOP

SUB RXD
 Pause 100 'Allow all of message to arrive in buffer
 Local T$ 'String for use ONLY inside this sub
 Do 'Suck message from COM port buffer:
   T$=INPUT$(1,#2) 'Suck a byte from the buffer
   If T$=Chr$(13) Then Exit Do 'If it is a CR byte, hop out of this loop
   MSG$=MSG$+T$ 'Otherwise, add the byte to the MSG$ string
 Loop 'Do it all again, till a CR byte IS found...
END SUB