The Little Man Computer – Reference The little man’s instruction set: These are all the instructions the little man can execute. Instruction Mnemonic Machine Code Load LDA 5xx Store STA 3xx Add ADD 1xx Subtract SUB 2xx Input INP 901 Output OUT 902 End HLT 000 Branch if zero BRZ 7xx Branch if zero or positive BRP 8xx Branch always BRA 6xx Data storage DAT xx refers to a Mailbox number (Memory Address) Example (Using Machine Code) Instruction Address What it does: Mnemonic Machine Code 00 INP 901 Input a number and put it in the calculator Store the number in the calculator in 01 STA 99 399 memory slot 99 02 INP 901 Input a number and put it in the calculator Add the number in memory slot 99 to the 03 ADD 99 199 number in the calculator Output the number which is now in the 04 OUT 902 calculator 05 HLT 000 Halt
The Little Man Computer – Reference The little man’s instruction set: These are all the instructions the little man can execute. Instruction Mnemonic Machine Code Load LDA 5xx Store STA 3xx Add ADD 1xx Subtract SUB 2xx Input INP 901 Output OUT 902 End HLT 000 Branch if zero BRZ 7xx Branch if zero or positive BRP 8xx Branch always BRA 6xx Data storage DAT xx refers to a Mailbox number (Memory Address) Example (Using Machine Code) Address Instruction What it does: Mnemonic Machine Code 00 INP 901 Input a number and put it in the calculator 01 STA 99 399 Store the number in the calculator in memory slot 99 02 INP 901 Input a number and put it in the calculator 03 ADD 99 199 Add the number in memory slot 99 to the number in the calculator 04 OUT 902 Output the number which is now in the calculator 05 HLT 000 Halt
cpu_lmc_machine_code_ref.docx