A lot of retrocomputers have been documented by inspecting their boards, disassembling their ROMs, reverse engineering their internals, and documentation is widely available online. But the Sanco 8003 is a French/Japanese computer for which we found no documentation at all, as of 2023: nothing about the hardware, nothing about the software, just a few hints that it has a Z80 and can run the famous CP/M operating system. There are some amateurs here and there, but we virtually found no "hard scene" for this computer.

In this talk, we are going to describe our journey in documenting this computer. We will show how we tore it apart, how we dumped the ROMs, how we leveraged some self-built custom hardware tools, how we followed the traces on the circuit board, how we understood the 74xx logic gates, how we disassembled the ROM and patched it to run our custom bootloader, how we experimented with sideloaded assembly to confirm (or deny) the expectations we thought of by looking at the reconstructed schematics, and, eventually, how we wrote our own emulator.

Everything we do is freely accessible and publicly available as a git repository, so you can contribute too! There is a lot of work that still needs to be done, so any contribution is welcome!