8051 Disassembler

See where bytes sit in code memory, internal RAM and special function registers. Work with firmware whose source is unavailable, inspect compiler output or teach 8051 memory layouts. Install from the Microsoft Store or with winget and open HEX files in seconds, with nothing to configure.

Point it at an Intel HEX file and you get the program back the way the chip sees it: every byte at its address, decoded to MCS-51 assembly, with special function registers, bit addresses and interrupt vectors named instead of left as numbers. Hover any instruction to see what it does. You stop translating opcodes in your head and start reading the program. When you need it as source rather than a listing, export it to a .asm file that assembles back to the byte-identical image.

The memory map labels the entry points for you - reset, external 0, timer 0, external 1, timer 1 and the serial vector - each flagged at its address with the handler sitting there. On an unfamiliar binary this is usually the fastest way in: you can see which interrupts the firmware actually uses before reading a single line of it.