Several well-crafted web tools serve the community, each with distinct strengths:
Click the button and review the generated assembly code.
0000 C3 20 10 JP $1020 0003 00 NOP ... 1020 AF XOR A 1021 32 00 50 LD ($5000), A
Modern online disassemblers like those offered by ClrHome, coupled with powerful professional tools like z80dasm , have made this process more accessible than ever. They are the keys that unlock the machine's soul, translating the cryptic language of binary opcodes back into the human-readable mnemonics of Z80 assembly.
(simcoup.net): Focused on Game Boy and Sega Master System disassembly (Z80-based but with slight differences). It includes a useful "export to ASM" feature that generates code ready for reassembly with popular assemblers. z80 disassembler online full
: A GitHub-hosted tool that identifies strings and data areas automatically, with specialized support for Amstrad CPC ROMs. Quick Technical Reference
Here is what happens when you upload your "Galactic Conqueror" ROM to a full online disassembler:
Some legacy applications physically alter their own instructions in RAM while executing. Static disassemblers cannot detect these dynamic runtime changes.
The ideal "full" disassembler is the one that best fits your specific project and workflow. For a one-stop, all-encompassing solution with a GUI, is an excellent choice. If you prefer the precision and integration of a command-line tool, z88dk-dis or z80dasm are top contenders. For tackling large, undocumented codebases with automated analysis, the z80-smart-disassembler is a unique asset. Finally, for pure web convenience without any installation, the Cemetech Online Disassembler or z80js provide immediate, accessible functionality. Several well-crafted web tools serve the community, each
Instantly accessible via browser on any operating system (Windows, Linux, macOS).
Before diving into specific tools, it is essential to understand what elevates a basic disassembler to a professional-grade reverse engineering utility. A “full” tool goes beyond simply converting byte values to mnemonics. It provides features that are crucial for reconstructing original source code from raw binaries.
Instructions like LD A, (IX+5) use relative offsets. If an online disassembler is not completely precise, it may miscalculate target pointers that rely on calculated index register math.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. They are the keys that unlock the machine's
The Z80 uses prefix bytes ( $CB , $DD , $ED , $FD ) to shift into secondary opcode tables. Correctly tracking these multi-byte sequences is critical for accurate decoding.
https://www.masswerk.at/z80/disassembler/ – Handles many undocumented instructions, supports origin, can embed labels via syntax.
Instead of forcing you to read hardcoded memory addresses like JP 0x12A4 , a robust disassembler automatically generates labels (e.g., LABEL_12A4: ) at target destinations and replaces the hex addresses in the code instructions with those labels.