If you want just the to check out right now:
: Allows users to manually mark specific memory regions as code or data to refine the disassembly results.
A disassembler is a program that takes machine code (binary) as input and translates it into assembly language. This process is also known as reverse compilation or decompilation. The goal of a disassembler is to recreate the original assembly code from the binary data, making it easier to understand and analyze.
if (!instruction) disassembly.push(` Unknown opcode $opcode at PC=$pc`); pc++; continue; z80 disassembler online full
Z80 Disassembler Online Full: Top Tools for Retro Engineering in 2026
disassembly.push(` $instruction.mnemonic $operands.join(', ')`); pc += instruction.bytes;
Locate the main entry points. If it is a system ROM, the entry point is typically 0000h or the Interrupt Service Routines (ISRs) at 0038h . Start the disassembly trace from these points. Step 3: Separate Code from Data If you want just the to check out
Since retro development often happens across different operating systems, having a browser-based tool is invaluable. Here are the most robust online and cloud-based disassemblers available today:
: A comprehensive online development environment that includes an editor, assembler, and disassembler. It supports saving files online, building projects, and exporting binaries. Z80 Studio
: The best choice if you are working with specific Z80 variants like the Spectrum Next (Z80N) The goal of a disassembler is to recreate
Want infinite lives in Manic Miner on the ZX Spectrum? Load the game ROM into a full online disassembler. Search for the number 3 (starting lives) in the hex dump. Look for a DEC A (decrement accumulator) or SUB 01 instruction near that data. Replace it with NOP or INC A . Reassemble and patch the ROM.
If you prefer offline tools, z80dasm and z80ex are simple command-line disassemblers; combine with objdump-like frontends or custom scripts for labeling and formatting.
A Z80 disassembler takes raw binary data (ROM images, binaries, or hex dumps) and converts it into Z80 assembly code ( LD A, B , CALL , RET , etc.). Unlike a decompiler which attempts to reconstruct high-level language, a disassembler maps directly to assembly mnemonics.
while (pc < binaryData.length) const opcode = binaryData[pc]; const instruction = z80Instructions[opcode];