$regfile = "m8515.dat"
$crystal = 1000000
$baud = 19200
Dim X As Byte , Y As Byte
Config Portb = Output
Config Portd = Input

Set Portd
Portb = 255
Wait 1
Portb = 0
Dim a As Byte 
Dim b As Byte 
Dim c As Byte 

a=1
c=255

Do
 If Pind.0 = 1 Then a=1
 else If Pind.1 = 1 Then a=2
 else If Pind.2 = 1 Then a=3
 else If Pind.3 = 1 Then a=4
 else If Pind.4 = 1 Then a=5
 else If Pind.5 = 1 Then a=6
 else If Pind.6 = 1 Then a=7
 else If Pind.7 = 1 Then a=8

 if a=1 then b=b+1
 if a=2 then b=b-1
 if a=3 then shift b, left
 if a=4 then shift b, right
 if a=5 then rotate b, left
 if a=6 then rotate b, right
 if a=7 then b=256-b
 if a=8 then swap b,c

 Portb=b
 Waitms 200

Loop