: Clean list of mnemonics alongside their memory addresses.
Decrements the B register and jumps if the result is not zero (loops). Hardware I/O
There is no better way to learn than reading working code. Download a small, well-known utility ROM for the Amstrad CPC. Run it through a Z80 disassembler online full version, and study how professional programmers saved registers, handled interrupts (IM 1 vs. IM 2), and created lookup tables.
: Programs often expect to reside at a specific memory location (like 0x100). If you don't set the correct load address, your jumps and calls will point to the wrong places. Separate Code from Data z80 disassembler online full
Ideally something like z80dasm (command-line) but accessible in a browser.
Does anyone know a better full online tool? Or a way to run z80dasm in a browser (WASM, JS port)?
To visualize what the online disassembler does automatically behind the scenes, consider this sample mapping table: Hexadecimal Bytes Decoded Mnemonics Architectural Meaning 21 00 40 LD HL, 4000h : Clean list of mnemonics alongside their memory addresses
Z80 code is highly position-dependent. An online tool must allow you to specify the starting memory address (e.g., $0000 for standard ROMs, $4000 for ZX Spectrum RAM files, or $0100 for CP/M applications). Incorrect origin mapping breaks relative jumps and memory references. 2. Data vs. Code Separation
Many retro programs dynamically alter their own instructions in RAM during execution to save cycles. Static disassemblers cannot predict these runtime changes, requiring manual developer review. Step-by-Step Workflow for Online Disassembly
While heavy-duty desktop tools exist, a suite provides a zero-install, cross-platform alternative. This comprehensive guide explores how online Z80 disassemblers function, how to use them effectively, and what features to look for when reversing legacy binaries. What is a Z80 Disassembler? Download a small, well-known utility ROM for the Amstrad CPC
Allows users to manually mark specific memory addresses as code, data, or text to clean up the output dynamically. Why Use an Online Z80 Tool?
This could be a ROM dump from a classic console, a snapshot file, or simply a small program you wrote. For our example, we'll use a small, manually created sequence of bytes.
Whether you're fixing a bug in a 40-year-old arcade game or just curious about how 8-bit math works, the right online tool makes the past readable again.