'============================================================================
'                  PCIORX.BAS - PARALLEL FILE TRANSFER
'
' (c)Copyright Sealevel Systems Incorporated, 1993 - 1995
'
'                  RECEIVES A FILE UP TO 65535 BYTES LONG
'                  BOARD BASE ADDRESS = 378 HEX
'                  CONSULT THE READ.ME FILE FOR A CABLE WIRING DIAGRAM
'============================================================================
       
        CLS
        DEFINT B, I

        PORTA = &H378                           'DATA PORT = BASE ADDRESS
        PORTB = &H379                           'STATUS PORT = BASE+1
        PORTC = &H37A                           'CONTROL PORT = BASE+2

        OUT PORTC, &H20                         'SET PORTA = INPUT MODE

        RXREADY = &H24                          'PORTC BIT D2 = RX READY BIT
        RXBUSY = &H20

        DATAVALID = &H40                        'PORTB BIT D6 = DATA READY BIT
'============================================================================
'                       RECEIVE THE FILE SIZE
'============================================================================

        PRINT "Filename = RECEIVED.DAT"
        PRINT "Filesize (bytes) = "
        PRINT "Receiving byte # "
        GOSUB READBYTE                                  'GET MSB OF FILESIZE
        FSIZE = BYTE * 256
        GOSUB READBYTE                                  'GET LSB OF FILESIZE

        FSIZE = FSIZE + BYTE
        LOCATE 2, 20: PRINT FSIZE
                   
        DIM BUFFER(FSIZE)                               'SET UP A BUFFER

        FOR X = 1 TO FSIZE                              'READ THE FILE
        GOSUB READBYTE
        LOCATE 3, 18: PRINT X                           'PRINT BYTE COUNT
        BUFFER(X) = BYTE
        NEXT X                                          'LOOP UNTIL DONE

        PRINT "Writing file to disk..."

        OPEN "RECEIVED.DAT" FOR BINARY AS #1
        FOR X = 1 TO FSIZE
        PUT #1, X, BUFFER(X)
        NEXT X
        CLOSE #1

        END


READBYTE:
'============================================================================
'                        SET RECEIVER READY
'============================================================================

        OUT PORTC, RXREADY                      'SET RX READY BIT HIGH

'============================================================================
'                       WAIT FOR DATA VALID
'============================================================================

        DO                                      'WAIT FOR DATA READY
        LOOP WHILE (INP(PORTB) AND DATAVALID) <> DATAVALID
        
'============================================================================
'                  DATA AVAILABLE - SET RECEIVER BUSY
'============================================================================

        OUT PORTC, RXBUSY                       'SET RX READY BIT LOW

'============================================================================
'      WAIT FOR DATA VALID TO GO LOW (WAITS FOR DATA STROBE TO FINISH)
'============================================================================

        DO
        LOOP WHILE (INP(PORTB) AND DATAVALID) = DATAVALID

'============================================================================
'                              READ DATA
'============================================================================

        BYTE = INP(PORTA)                               'READ THE DATA PORT
        RETURN