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

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

        NODATA = 0                              'PORTC BIT D2 = DATA READY BIT
        DATAREADY = 4

        RXREADY = &H40                          'PORTB BIT D6 = RX READY BIT

        OPEN "PCIOTX.BAS" FOR BINARY AS #1      'FILE TO TRANSMIT

'============================================================================
'                       READ IN THE ENTIRE FILE
'============================================================================

        CLS
        PRINT "Reading the file..."
        FSIZE = LOF(1)                          'GET THE FILESIZE
        DIM BUFFER(FSIZE)
        FOR X = 1 TO FSIZE                      'READ IN THE FILE
        GET #1, X, BUFFER(X)
        NEXT X                                  'LOOP UNTIL DONE

'============================================================================
'                       SEND THE FILESIZE
'============================================================================
       
        PRINT "Transmitting file PCIOTX.BAS"
        PRINT "Filesize (bytes) = "; FSIZE
        PRINT "Sending byte # "

        BYTE = FSIZE \ 256
        GOSUB SENDBYTE                          'SEND MSB OF FILESIZE
        BYTE = FSIZE AND 255
        GOSUB SENDBYTE                          'SEND LSB OF FILESIZE
           
        FOR X = 1 TO FSIZE                      'TRANSMIT THE FILE
        BYTE = BUFFER(X)
        GOSUB SENDBYTE                          'SEND A BYTE
        LOCATE 4, 16: PRINT X                   'PRINT BYTE COUNT

        NEXT X                                  'LOOP UNTIL DONE
        END

'============================================================================
'                           EXIT THE PROGRAM         
'============================================================================

XIT:    OUT PORTC, NODATA                        'LOWER DATA READY BIT   
        CLOSE #1
        END

'============================================================================
' SENDBYTE SUBROUTINE - WAITS FOR RECEIVER READY BEFORE STROBING OUT DATA
'============================================================================

SENDBYTE:
        OUT PORTC, NODATA                         'LOWER DATA READY BIT

'============================================================================
'                       WAIT FOR RECEIVER READY
'============================================================================

        FOR TIMEOUT = 1 TO 50000
                IF (INP(PORTB) AND RXREADY) = RXREADY THEN GOTO ACK
        NEXT TIMEOUT
        PRINT
        COLOR 0, 7
        PRINT "TIMEOUT WAITING FOR RECEIVER - TRANSFER ABORTED"
        COLOR 7, 0
        GOTO XIT

'============================================================================
'                       RECEIVER READY - SEND DATA
'============================================================================

ACK:    OUT PORTA, BYTE                         'SET DATA TO PORT A D0 - D7
        OUT PORTC, DATAREADY                    'RAISE DATA READY BIT 

        FOR DLY = 1 TO 100: NEXT DLY             'DELAY TO CREATE A STROBE

        OUT PORTC, NODATA                       'LOWER DATA READY BIT  
        RETURN