Machine Language & Assembly

Binary · Opcodes · Registers

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How a CPU's only true language works — binary opcodes, operands, registers, the fetch-decode-execute cycle, and why assembly exists.

By the end, you can

Explain what machine code is and why it is the only language a CPU truly understands.
Identify the opcode and operand fields in a binary instruction and state what each does.
Convert a small value (e.g., 5, 42, 179) to its 8-bit binary representation.
Name the four registers introduced (AL, BL, CL, DL) and explain what registers are for.
Trace the fetch-decode-execute cycle step by step for a short three-instruction program.
Predict the value in AL after a sequence of MOV and ADD instructions.
Explain why a single flipped opcode bit silently corrupts a program.
Distinguish what an assembler does from what a compiler does.
Contrast x86 (CISC, variable-length) and ARM (RISC, fixed 32-bit) instruction encoding.
Order the three layers of the language stack from highest to lowest abstraction.

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