dim myfilename as fred.txt"   'file name
dim mytxt as string*20  'some random text
dim flength as long  'file length
dim n as long 'pointer
dim tempb as byte 'temporary byte

do
    chdir "\"   'to root dir
    open myfilename for binary as #128
   'flength = filelen(myfilename)+1
   mytext = "hello neil"
   put #128 , mytxt  
   mytxt = "goodby"
   put #128 , mytxt
   flush #128
   close #128

    waitms 5000
   'now see what has been written
    print #1 , ""
    print #1 , "reading file"
    open myfilename for binary as #128

 
   flength = filelen(myfilename)

   for n = 1 to flength
      get #128 , tempb , n
      print #1 , "var=" ; chr(tempb)
   next

   close #128


loop

put #128 , mytxt, flength

 

$regfile = "m1284pdef.dat"
'$regfile = "m1284def.dat"
$crystal = 9830400                                          '10000000

$framesize = 500                                            ' This lib only uses ~10 $hwstack - please see the application note for more information
$hwstack = 500                                              ' This lib only uses ~10 $hwstack - please see the application note for more information
$swstack = 500                                              ' This lib only uses ~10 $hwstack - please see the application note for more information

$PROG &HEF,&HC7,&HD0,&HFD
,---------------------------------------------------                                
'Set up watchdog
'--------------------
 config watchdog = 8192               '8 secs
 start watchdog


 '----------------------------------
'Declare variables
'-----------------------------------
'dim dtstamp as string *16
dim f as byte
dim index as byte
Dim n As word
dim k as dword
dim filenamestr as string * 25
dim writeposn as long
dim dstr1 as string * 100

 '------------------------------------------
 'Declare constants



'----------------------------------------------



declare Sub Save_to_sdcard1()
' '-------------------------------------------------------------------------------
'Open a software UART TRANSMIT channel for debug dB9
'-------------------------------------------------------------------------------
'Open a software UART TRANSMIT channel for debug dB9
Open "comc.3:38400,8,n,1" For Output As #1                   '








 '------------------------------------------
 'Setup ports
 '------------------------------------------
   Heartbeatled Alias Portb.1                               'heartbeat led
   Config Heartbeatled = Output




  '*******************************************
  'MAIN LOOP
  '*******************************************


  startup:

'set up SD card
  $include "config_mmcsd_hc.inc"                              'set up the high capacity SD card comms
  F = driveinit()
If F <> 0 Then
   Print "SD init error"

   End
else
   print #1, "Good drive"    'we can now install DOS

End If

' Mount filesystem
$include "config_AVR-DOS.inc"
F = Initfilesystem(1)
If F <> 0 Then
   Print "FAT init error"
   End

else
  print #1,"good mount. SD card all good"
End If

  k = 0
  filenamestr = "name1.txt"

  do

      reset watchdog

      waitms 250

     'change file name every 50 secs, create and write to a new file name
      incr k
      n = k mod 100
      if n = 0 then
        filenamestr = "new file name" + str(k) + ".txt"
        filenamestr = right(filenamestr,12)          'maintain short name 8.3
      end if

       call save_to_sdcard1()

       toggle portB.1         'flash a led

      waitms 250

  loop


'***************************************************************************



 '***********************************************************************
Sub Save_to_sdcard1()


         disable interrupts
         Chdir "\"
         dstr1 = "_hello_" + str(k) + ","                          'dstr1 = payload

        open filenamestr for binary As #128                       'fist write will overwrite the file

        print #1,"myfilenamestr=";filenamestr

         print #1,"seek before PUT =";seek(#128)
         print #1,"lof  before PUT =";lof(#128)
         print #1,"loc  before PUT =";loc(#128)

         put #128,dstr1,writeposn,len(dstr1)

         print #1,"seek after PUT =";seek(#128)
         print #1,"lof  after PUT =";lof(#128)
         print #1,"loc  after PUT =";loc(#128)
         writeposn = seek(#128)           'find where to append fotr the next PUT operation
         print #1, "k= ";k
         print #1, "filelength = ";filelen(filenamestr) 'just checking

         Flush #128
         Close #128
         enable interrupts
         Print #1 , "{027}[92m";">> Saving to SD done"; "{027}[0m"   'green
         Print #1 , ""
         Chdir "\"
         exit sub


End Sub
 '****************************************************************************