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Pac-Man written in C, running on RISC-V in ASM Editor

The best web IDE for Assembly
M68K, MIPS, RISC-V, x86-64, Z80
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Documentation

The editor comes with built-in documentation for the M68K, MIPS, RISC-V, x86-64 and Z80 instruction sets including the valid addressing modes, description and examples for each instruction, directive and syscall. Visit the documentation

Documentation for agents

Send this message to an AI assistant so they can search the docs of each Instruction Set.

Look at https://asm-editor.specy.app/llms.txt for information on how to use ASM Editor's documentation for M68K, MIPS, RISC-V, X86 and Z80 Assembly languages.

Code completion

Write and learn faster with the code completion tools, suggesting you with the valid addressing modes and shortcuts for labels and other keywords. Real time semantic errors that warn you before you compile the code.

Tools & Customisation

Feature rich tools to help you debug your code. Includes breakpoints, stepping, undo, poking registers and memory, stack tracer, register/memory diffing, decimal/hexadecimal conversions, stdout/stdin/errors, customisable shortcuts and settings, formatter and more. You can also customise the theme of the editor to your liking.

Compile from C/C++

Write C or C++ and compile it to MIPS, RISC-V or x86-64 assembly at any optimization level, with GCC, or Clang on MIPS and RISC-V. C source lines are mapped to the assembly instructions so you can see how loops, function calls and expressions become assembly.

Reverse engineering & CTFs

Import an x86-64 Linux ELF executable, to disassemble it, decompile it to C-like pseudocode with the Ghidra decompiler and edit its bytes in the hex editor. Rename functions, add comments, browse its strings and debug it with breakpoints, stepping and undo. Made for capture the flag challenges, cybersecurity courses and learning how compiled programs work. Read about Executables

Peripherals

Programs can draw on a screen and interact with the user through mouse and keyboard or use the terminal for stdout and stdin. Available for M68K, MIPS, RISC-V and Z80. This can also be used to write simple interactive games and programs.

Exam

Create exams for students with the Exam tool
where the editor is locked down.

Embed

Embed the editor in your website to show and teach how assembly works using the Embedder tool

Published research

ASM Editor is described in a peer-reviewed paper presented at the 2026 IEEE Global Engineering Education Conference, together with the first-year course it was built for.

E. Menichelli and L. Forlizzi, “ASM Editor: Understanding Language Abstractions Through Assembly Programming”, 2026 IEEE Global Engineering Education Conference (EDUCON), Cairo, Egypt, 2026.

Read the paper