naja, habs mir lang angesehen und keinen Fehler gefunden...

Code:
$prog , 255 , &B11011001 ,
$regfile = "m2560def.dat"
$hwstack = 82
$framesize = 68
$swstack = 68
$crystal = 16000000

Config Pind.5 = Output
Led Alias Portd.5

Config Com4 = 9600 , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

Config Timer1 = Timer , Prescale = 1024
On Timer1 Isrtimer1
Enable Interrupts
Enable Timer1
Timer1 = 49910

Open "com4:" For Binary As #4

Dim Thour As Integer
Dim Tmin As Integer
Dim Tsec As Integer
Dim Tday As Integer

Do
Loop


Isrtimer1:
Timer1 = 49910
Toggle Led
Tsec = Tsec + 1

If Tsec = 60 Then
   Tsec = 0
   Tmin = Tmin + 1
   End If
If Tmin = 60 Then
   Tmin = 0
   Thour = Thour + 1
   End If
If Thour = 24 Then
   Thour = 0
   Tday = Tday + 1
   End If

'Print "RT: " ; Thour ; ":" ; Tmin ; ":" ; Tsec
Print #4 , "RT: " ; Thour ; ":" ; Tmin ; ":" ; Tsec
Return

End