Instruction guardrails #26
Description
We should consider improving input validation for some of the commands.
In particular, we should ensure that the program in memory actually has a stop instruction before allowing the user to start a buffered sequence.
We may also want to ensure that output state definitions only set the first 16 bits high (since they are stored and passed internally as 32-bits). I'm not entirely sure what happens if you try to set higher pins...