Hexscope is a lightweight, high-performance binary hex viewer built as a dual-target binary polyglot. From a single, identical file (hexscope.com), it executes natively as a 16-bit DOS COM program on legacy hardware or DOS emulators like DOSBox and 86Box, and as a 64-bit Linux ELF executable on modern UNIX environments.
Designed with a first-principles, pragmatic engineering approach, Hexscope avoids heavy abstractions, relying entirely on raw assembly, direct video memory manipulation (for DOS), and optimized ANSI terminal controls (for Linux).
A binary polyglot is a single file that satisfies the execution requirements of multiple distinct operating systems or architectures simultaneously.
Hexscope achieves this by carefully overlaying binary structures:
- The ELF Header Overlap: The beginning of the file contains a valid 64-bit ELF header (
0x7F "ELF"), complete with program headers pointing to the Linux entry point. - The DOS Execution Stub: Buried safely within the header offsets, a short jump instruction (
jmp dos_start) diverts DOS execution past the Linux structures directly into the real-mode 16-bit payload.
Neither operating system gets confused by the foreign headers present in its address space - each parser extracts only the sections relevant to its own runtime environment.
- Dual Platform Native: Runs without modification on MS-DOS 6.22 (and compatible DOS environments) and 64-bit Linux distributions (tested on Ubuntu 24.04 LTS).
- Interactive Navigation: Seamlessly scroll through files using arrow keys, Page Up / Page Down, and Home / End shortcuts.
- Comprehensive Byte Inspection: Displays live status information for the selected byte, including its hexadecimal offset, hex value, decimal value, 8-bit binary representation, and total file size.
- Read-Only Safety: Strictly read-only file inspection designed to prevent accidental data corruption.
- Polyglot Build Automation: Includes a single unified build script that functions natively in both Windows Command Prompt (
cmd.exe) and Linux Bash.
| Key | Action |
|---|---|
| Left / Right Arrows | Move selection to the previous or next individual byte. |
| Up / Down Arrows | Move selection up or down by a full row (16 bytes). |
| Home | Jump to the beginning of the current 256-byte page. |
| End | Jump to the very last byte of the file. |
| Page Up / Page Down | Scroll through the file in 256-byte page increments. |
| Q / ESC | Quit and exit the application, restoring terminal settings or video modes. |
├── hexscope.asm # Core assembly source code (MASM / NASM compatible syntax)
├── build.bat # Unified polyglot build script (runs on Windows and Linux Bash)
└── README.md # Project documentation
To assemble and build Hexscope from source, you will need:
- NASM (Netwide Assembler) installed and available in your system path.
- A target environment for testing (e.g., 86Box, DOSBox, or a Linux terminal).
Hexscope features a unified polyglot build script (build.bat) that works seamlessly across platforms without needing separate Makefiles or batch files.
Open your terminal in the source directory and run:
bash build.bat(The script will automatically assemble the binary using NASM and apply executable permissions via chmod +x).
Switch to the source directory and run:
build.bat
Pass any target file as a command line argument:
./hexscope.com hexscope.comBoot your DOS environment and execute the compiled binary with a filename argument:
HEXSCOPE.COM RUNME.COM
- DOS Mode: Bypasses standard I/O bottlenecks by writing directly to video memory segment
0xB800using direct character and attribute word writes, combined with standard DOS INT 21h file handles and INT 16h keyboard polling. - Linux Mode: Configures terminal attributes via
termiossystem calls to enable raw input mode (disabling canonical buffering and local echo), renders output via standard Linuxsys_writesyscalls, and positions the cursor precisely using ANSI escape sequences.
