How to pronounce“opcode”in English

That opcode 1000 is an ADD instruction.

In this case the opcode, which is the first four bits, is: 0010.

6.26 trio display up and same opcode out is pornper

But there is no instruction with an opcode of 0, and so the computer would have crashed!

Again, those first four bits are our opcode which corresponds to a “LOAD_A” instruction.

So instruction sets tend to keep getting larger and larger keeping all the old opcodes around for backwards compatibility.

For example, there’s over a dozens different opcodes just for variants of ADD!