He was soaring. The controls were janky, the draw distance a foggy abyss, and citizens of Metropolis were T-posing on street corners. But Leo was flying. He punched a helicopter. He caught a falling taxi. He hovered above the Daily Planet globe and felt, for a single, glorious frame, like a god.
Impossible. Suspicious. Perfect.
He laughed. A genuine, unhinged laugh. The compression algorithm was black magic. It had taken a city, crumpled it into a ball the size of a walnut, and then ironed it back out on his hard drive.
The installer was a work of digital origami. A command prompt flashed, scrolled ancient runes of code, and then a progress bar appeared with the label: Decompressing Metropolis (this will take a minute) .
And for one night, in a dingy dorm room, a man could fly.
He ran it.
The screen went black. A single piano key chimed. The John Williams theme began—but it was a MIDI version, tinny and triumphant. The title card appeared: SUPERMAN RETURNS . Below it, in Comic Sans: "CRACKED BY: LexLuthor2006 / THANKS FOR SEEDING, LOSERS"
At 4:58 AM, the download finished. His heart hammered against his ribs. He double-clicked the archive.
This LMC simulator is based on the Little Man Computer (LMC) model of a computer, created by Dr. Stuart Madnick in 1965. LMC is generally used for educational purposes as it models a simple Von Neumann architecture computer which has all of the basic features of a modern computer. It is programmed using assembly code. You can find out more about this model on this wikipedia page.
You can read more about this LMC simulator on 101Computing.net.
Note that in the following table “xx” refers to a memory address (aka mailbox) in the RAM. The online LMC simulator has 100 different mailboxes in the RAM ranging from 00 to 99.
| Mnemonic | Name | Description | Op Code |
| INP | INPUT | Retrieve user input and stores it in the accumulator. | 901 |
| OUT | OUTPUT | Output the value stored in the accumulator. | 902 |
| LDA | LOAD | Load the Accumulator with the contents of the memory address given. | 5xx |
| STA | STORE | Store the value in the Accumulator in the memory address given. | 3xx |
| ADD | ADD | Add the contents of the memory address to the Accumulator | 1xx |
| SUB | SUBTRACT | Subtract the contents of the memory address from the Accumulator | 2xx |
| BRP | BRANCH IF POSITIVE | Branch/Jump to the address given if the Accumulator is zero or positive. | 8xx |
| BRZ | BRANCH IF ZERO | Branch/Jump to the address given if the Accumulator is zero. | 7xx |
| BRA | BRANCH ALWAYS | Branch/Jump to the address given. | 6xx |
| HLT | HALT | Stop the code | 000 |
| DAT | DATA LOCATION | Used to associate a label to a free memory address. An optional value can also be used to be stored at the memory address. |