ROM Descrambling Utility

This is a small tool that helps decoding ROMs that have their address and data lines swapped.

It allows you to remap address and data lines. Changes are shown in realtime using a hex+ASCII view, allowing for WYSIWYG decoding.

Usage

rom-descrambler input.bin

The tool will then open its main window.

Keys

Global keys:

• O - show Options dialog
• S - show "Save descrambled data" dialog
• Q - quit

Hex view:

• cursor keys: scrolling (up/down: 1 line, left/right: 1 byte)
• page up/down: scroll up/down by 1 page
• home/end: jump to beginning/end of the file
• +/- - increase/decrease number of bytes per line
• G - show Go To Offset dialog
• V - change view mode (original, descrambled, side-by-side)
• M - go to Line Mappings

Line mappings:

• cursor keys - nagivate between address/data line mappings
• 'A' + number - jump to address line
• 'D' + number - jump to data line
• R - reverse all mappings
• 0..9 - change value (confirm by moving or Return, cancel using ESC)
• +/- - increase/decrease value
• ESC - go back to hex view

Compiling

In order to compile the tool, you will need CMake and NCurses. (PDCurses should also work.)

On Debian, this would be the following packages:

• cmake
• libncurses-dev

Various notes

Thanks to https://github.com/mrdudz/unidec for the inspiration for this tool.