riapyx

Spec sheet

Purpose

riapyx is an early PC (8086) emulator written in Rust, targeting Windows 3.0 in real mode.Read 9 Oct 2026 · github.com

License

The emulator code and test program are provided under the MIT license.Read 9 Oct 2026 · github.com

Build

The project is built with Cargo and uses rust-sdl2, whose platform installation instructions are referenced for Windows and OS X users.Read 9 Oct 2026 · github.com

Build requirements

The project is built with Cargo and uses rust-sdl2; its README points to platform installation instructions, mainly for Windows and OS X users.Read 9 Oct 2026 · github.com

Compatibility limits

It cannot boot ELKS or FreeDOS, and the README says installing an operating system is unlikely because floppy switching is unsupported and untested.Read 9 Oct 2026 · github.com

Debugger

Its debugger supports stepping, continuing, tracing, dumping RAM, breakpoints, memory display, disassembly, and quitting.Read 9 Oct 2026 · github.com

Disk images

The README recommends pre-installed hard-drive images because floppy switching is unsupported and installing an operating system is unlikely to work.Read 9 Oct 2026 · github.com

Distribution

The repository provides source files and Cargo build instructions; its README does not describe packaged downloads.Read 9 Oct 2026 · github.com

Emulated hardware

It emulates an Intel 8086 CPU, XT keyboard, limited CGA graphics, a serial port, a Microsoft serial mouse, and floppy and hard drives through BIOS calls.Read 9 Oct 2026 · github.com

Graphics

The emulated CGA adapter supports 80×25 16-color text mode and 640×200 2-color mode.Read 9 Oct 2026 · github.com

Graphics limits

CGA graphics support is limited to 80×25 16-color text mode and 640×200 2-color mode.Read 9 Oct 2026 · github.com

Hardware gaps

It does not emulate a programmable interrupt controller, programmable interval timer, DMA controller, or proper IDE hard and floppy drives.Read 9 Oct 2026 · github.com

Logging

Optional Cargo features provide CPU, display, mouse, serial, BIOS, storage, machine, and keyboard logs, among other debugging aids.Read 9 Oct 2026 · github.com

Operating systems

It can run MS-DOS 6.22 and Windows 3.0 in real mode; the README says it cannot boot ELKS or FreeDOS.Read 9 Oct 2026 · github.com

Original target

Its main target was running Windows 3.0 in real mode.Read 9 Oct 2026 · github.com

Performance

The maker says the emulator does not aim for good performance and received only minimal profiling and simple optimizations.Read 9 Oct 2026 · github.com

Usage

The command line accepts hard-drive and floppy images and lets the user choose which drive to boot.Read 9 Oct 2026 · github.com

Where Specifiction places it

• MS-DOS Emulators#25 of 266.6