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Revision as of 03:39, 15 September 2009 by imported>Clippy
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The LOC function returns the status of a Serial(COM) port receive buffer or current position in a file.

Syntax: bytes% = LOC(open_number)

  • The parameter used is the number used in the port OPEN AS statement.
  • Returns 0 if the buffer is empty. Any value above 0 indicates COM has received data.
  • Use it in conjunction with INPUT$ to get the data bytes received.
  • Can also be used for the current position in a file routine. See: SEEK

Example: Reading and writing from a COM port opened in Basic.

OPEN "COM1: 9600,N,8,1," FOR RANDOM AS #1 LEN = 2048 'input and output
DO: t$ = INKEY$ ' get any transmit keypresses from user
IF LEN(t$) THEN PRINT #1, t$ ' send byte to UART transmit buffer"
bytes% = LOC(1) ' bytes in buffer
IF bytes% THEN ' check UART receive buffer for data"
r$ = INPUT$(bytes%, 1) ' get bytes in the receive buffer"
PRINT r$; ' print characters consecutively to screen"
LOOP UNTIL t$ = CHR$(27) ' Escape exit and CLOSE #1"

See also: PRINT, PRINT (file statement)


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