On the Subject of Caesar Cipher

Communication was dangerous back in the days. Can you figure out what the original message was?

Decipher the characters on the display with the help of Caesar’s tactics. There’s no delete button, so press those buttons carefully!

For example: if the offset is -2, D becomes B and L becomes J. The table below can be used to calculate the required offset. If the offset column contains an = sign, that value should be used, regardless of other rules that apply.

Condition Offset
Serial number contains a vowel -1
Number of batteries +1 per battery
The last digit of the serial number is even +1
Indicator with label CAR is present +1
Parallel port and lit indicator with label NSA is present =0