Az assembly (gépi kódú) nyelveken a processzorok utasításait általában hárombetűs rövidítésekkel (mnenomic) szokták jelölni. Például a "jump" utasítás mnenomicja a "JMP" szokott lenni, vagy mondjuk az "A" regiszter értékadása LDA ("Load A").

(Ebből az egészből kb az a lényeg, hogy gépi kódban programozni nem sokban különbözik az autizmustól.)

Következik pár, kevésbé ismert opcode leírása:

Any of several undocumented and semi-mythical {machine instructions} with destructive side-effects, supposedly included for test purposes on several well-known architectures going as far back as the {IBM 360}. The {Motorola} {6800} {microprocessor} was the first for which an HCF {opcode} became widely known. This instruction caused the processor to {toggle} a subset of the {bus} lines as rapidly as it could; in some configurations this could actually cause lines to burn up.

KAH - Kill All Humans

Processor will push the status of the flags to the stack, and will then attempt to kill all humans.

This works much like 'Kill Some Humans' (KSH) but there is no way to set a maximum bodycount. Instead, with KAH, the immediate operand and ALU contents are ignored.

Note: on the second edition of this CPU, this opcode can be masked by pulling low the "/safe" pin, and this is the recommended usage.