Virtual80x86

A data-driven, C#-based x86 hobby emulator for DOS, Linux, and beyond.
Real, Protected, and Virtual 8086 modes. With devices. With paging. With insight.

Written between 2010 and 2016. Tinkered with ever since. Only uploaded to Github in 2025

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🧠 Why This Exists

“I looked at the Bochs source once... and decided I never wanted to do that again.”
— Chris (a.k.a. VBWizard)

Most x86 emulators bury their logic under macros and bit-parsing spaghetti.
Virtual80x86 is different.

It was built from the ground up in C#, designed to be clear, inspectable, and extensible.
Every instruction is decoded through a clean, XML-driven system.
Every device is modeled in structured, testable, object-oriented code.
And every clock tick is a moment you can see.

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⚙️ Features

• ✅ Full x86 instruction decoding

  • XML-defined opcodes
  • Operand-aware parsing
  • Clean C# execution classes

• ✅ Instruction set coverage

  • 8086 / 80186 / 80286 / 80386 / 80486 / Pentium-era support
  • Progressive FPU coverage (missing many ops, but runtime-completable)

• ✅ Real/Protected/Virtual 8086 mode support

• ✅ Full paging with live TLB tracking

• ✅ DOS support

  • Boots directly to MS-DOS
  • EMM386 confirmed working
  • Real BIOS, hard drive (image) and floppy boot support

• ✅ Linux support

  • Boots 1.x-era Linux distros
  • Runs bash, ps, and multitasking loops
  • Live task name detection via TR-based reverse walk

• ✅ Custom BIOS + CMOS support

  • Custom CMOS image generator included
  • Configurable boot devices

• ✅ Memory Forensics

  • Memory usage heatmap
  • Real-time paging access overlay
  • CR3-aware task memory analysis

• ✅ GDT viewer

  • All descriptors visualized live
  • Ring-level coloring
  • Task awareness

• ✅ Process Overlay

  • Current task shown by name (e.g. bash, ps, swapper, etc.)
  • Ring detection
  • Updates per tick

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🧪 What’s Experimental

• ⚠️ FPU is partially implemented (many instructions missing)
• ⚠️ Some devices have diagnostic scaffolding but aren’t fully connected
• ⚠️ Many variables and classes will raise compiler warnings (by design or stubbing)

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📁 Project Structure

• Virtual80x86/

  • Core CPU emulation, memory, instruction decoding
  • Includes all devices (CMOS, PIT, HDC, Floppy, PS2, Serial, etc.)

• WindowsFormsApplication1/

  • The front-end UI for emulator control, visualization, and rendering

• CreateCMOSImage/, Create XML From OpCode List (CSV)/

  • Tools for support, boot prep, and instruction list maintenance

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💬 From the Author

“When I got interested in emulators, I looked at the BOCHS source code…
And thought, ‘There has to be a better way.’”

This is the result of that thought.

If you’re a systems geek, a reverse engineer, or someone who just wants to see a machine breathe, I hope this gives you joy.

Pull it. Explore it. Break it. Rebuild it.

Or just open the live memory viewer and marvel at the color of memory.

— Chris (a.k.a. VBWizard)

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📜 License

TBD by Chris. (Currently private / shared by permission)

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