This page describes the instruction format for the microcode in core revisions 4 and lower. 5 and higher use a different format.
This page only describes the opcode format, operand format is identical to the newer 12-bit operand format.
Instruction Format
We write instructions as {{{ ooooo Xxx yyy zzz }}} Where the o's are the instruction, x's are op1, y's are op2 and z's are op3
While the actual instruction in hex is then