DOSVisor vs riapyx

DOSVisor is a Windows project that runs some MS-DOS programs in a virtualized 16-bit real-mode environment using the Windows Hypervisor Platform API. It is presented as a demonstration of that API rather than a complete DOS emulator. Hardware virtualization handles the CPU, while software emulates the DOS layer. A custom Interrupt Vector Table uses CPUID instructions to trigger VM exits and intercept DOS interrupts. DOSVisor captures I/O requests but supports only a small set of common requests. Timing support includes the BIOS counter, RAM refresh toggle bit, system clock, RTC registers, clock interrupts, and DOS current-time calls; the 8253 PIT timer is not fully implemented. Keyboard handling monitors state, keeps a simple buffer, and passes input through interrupts. Basic terminal commands support simple text-based games and other basic programs. BIOS data areas and the Program Segment Prefix are allocated but mostly unpopulated. The free public repository contains bin and src directories, with no releases or packages listed.

riapyx has no write-up on Specifiction yet; its figures are above.