EMAC PRIMER Instruction Manual page 28

3) Single step again and the display will show "FF03 d3". The IN instruction has been executed and the PC
register was returned with the address of the OUT instruction.
Right after step three, the value of the DIP switch has been loaded into the A register and it can be viewed by pressing
"Func." then the "A/A.F." key. The value of the A register will be shown in the pair of digits on the left. Change the value of
the A register (in this program the flag values don't matter). Now do step one and you will see the digital output LEDs now
show the new value of the A register*. If you press "Step" three more times, the IN instruction will change the A register to
the value of the DIP switches again and the OUT instruction will display the new value of the A register on the digital output
LEDs.
* NOTE: The PRIMER was designed so the digital output LEDs will turn on when a logic 0 is output to a particular bit of
port A. So, for example, if 01h is output to the port all LEDs will be turned on except for LED 0, and if F0h is output to the
port, all LEDs will be turned off except LEDs 3 to 0.
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