$regfile = "attiny2313.dat"
$crystal = 8000000
config portb = output   'sets PortB to output
config portd = output   'sets PortD to output

pind.2 = 1                'enables the internal pull-up resistor

dim i as byte
dim digit(4) as byte
dim displ(4) as byte
dim storage(4) as eram byte
dim ex(4) as byte

ex(1) = 3                 'sets pins 3 to 6 of PortD to drive the digits
ex(2) = 4
ex(3) = 5
ex(4) = 6

digit(1) = storage(1)     'recals the last value from the eeprom
digit(2) = storage(2)
digit(3) = storage(3)
digit(4) = storage(4)

Enable Interrupts       'enables the interrupts and defines the label for the routine
Enable Int0
On Int0 button

portd = 255               'blanks the display
portb = 0

do

   for i = 1 to 4        'multiplexing the 4 digits and showing the correct values

      portb = displ(i)
      portd.ex(i) = 0
      waitms 1
      portd.ex(i) = 1

   next

loop
end

button:                   'on interrupt
                          'blank display
 portd = 255

 While pind.2 = 0        'debounce
 wend

 incr digit(2)            'increase the value by 1
 if digit(1) > 9 then

    incr digit(2)
    digit(1) = 0

 end if

 if digit(2) > 9 then

    incr digit(3)
    digit(2) = 0

 end if

 if digit(3) > 9 then

    incr digit(4)
    digit(3) = 0

 end if

 if digit(4) > 9 then

    digit(4) = 0

 end if

 storage(1) = digit(1)   'store in eeprom
 storage(2) = digit(2)
 storage(3) = digit(3)
 storage(4) = digit(4)
 displ(1) = lookup(digit(1), Dta)  'Lookup the right value for portb in the data table
 displ(2) = lookup(digit(2), Dta)
 displ(3) = lookup(digit(3), Dta)
 displ(4) = lookup(digit(4), Dta)

 waitms 250             'debounce

 While pind.2 = 0
 wend

 return

Dta:                     'values for portb to display 0 to 9

data 123, 9, 227, 203, 153, 218, 250, 11, 251, 219