📚 OpenKernel EDU3D3D

The learning lab

One instruction at a time.

Write a program. Step through it. Watch the machine change.

Emoji CPU lab

Ready · 0 cycles

Emoji program

Type LOAD, ADD, or another opcode then Space to insert emoji. Ctrl/⌘ + Enter runs or pauses; Escape pauses; Ctrl/⌘ + ] indents. Tab moves focus. Labels use a colon. Jumps use zero-based instruction addresses.

Instruction map and breakpoints (0)

Breakpoints stop before an instruction. Run resumes past the stopped breakpoint once; Step executes it directly. Editing source clears old breakpoints and machine state.

    CPU registers

    R0
    0
    R1
    0
    R2
    0
    R3
    0
    R4
    0
    R5
    0
    R6
    0
    R7
    0
    Program counter (PC)
    0
    Stack pointer (SP)
    255
    Flags
    Zero: off · Negative: off · Overflow: off
    Delay request
    0 ms
    Stacks and loop frames

    SP = 255 − data depth − call depth. The stack is separate from memory.

    Data stack (bottom → top)

    Empty

    Call return addresses (bottom → top)

    Empty

    Loop frames

    Empty

    Output and input

    Run a PRINT instruction to see output.

    Queued input: Empty

    Memory · 256 bytes · 0 nonzero

    Each cell shows address:value. R = read this step; W = written this step. Select a cell to inspect or initialize it before execution. Use arrow keys to move, Home/End for the row, and Ctrl/⌘ + Home/End for the whole memory.

    Reset before initializing memory. Stored values wrap to 0–255.
    Execution trace · 0 entries

    Recent entries below. Inspect any zero-based index to see complete detached before/after state.