🧑‍💻 🎓 ESAP --- Negative operands for load direct instructions

[jameshughes89]

Related Issues or PRs

Resolves #226

What

1. Remove the ability to have negative operands for the load direct instructions in the assembler (update syntax)
2. Add a warning to the load direct instructions where they are introduced.

Why

Turns out the system's underlying design can't handle negative 4 bit operands as they get padded with 0s to become 8 bits, thereby removing their ability to be negative.

Where

Assembler & topic introducing the instructions

How

1. Updated assembler valid syntax
2. Added a warning (it was a note, but I think a warning is better? Maybe Whatever)

Testing

👍 (assembler manually and built local to view warning)

Additional Notes

Actually discussed this in detail in lecture today. Fun thing to discuss.

Although hardware could probably be designed to deal with this, the additional complexity is not worth it.