OpenVSM

OpenVSM lets Proteus VSM components implement their simulation behavior and optional schematic graphics in Lua. One 32-bit openvsm.dll can serve many device types and instances; every component loads its configured script into an isolated Lua state.

Download a release · Read the user guide · Browse the documentation · Report an issue

A Z80 computer on a Proteus schematic: a real EPROM, RAM and glue logic, with the CPU and the serial chip modelled in Lua, running Microsoft BASIC. See the Z80 example.

A minimal model

This script implements a two-input NAND gate. The names in device_pins match the terminal names on the Proteus component.

device_pins = {
    {name = "A", on_time = 100000, off_time = 100000},
    {name = "B", on_time = 100000, off_time = 100000},
    {name = "Q", on_time = 100000, off_time = 100000}
}

function device_simulate()
    Q:set(1 - (A:get() * B:get()))
end

Install OpenVSM, configure the component with MODDLL=openvsm.DLL and LUA=device.lua, then place the script beside the Proteus project. The user guide covers device properties, script lookup, pins, buses, callbacks, graphics, and troubleshooting.

Examples

Example	What it demonstrates
NAND	The smallest useful digital model
Active display	Lua drawing and mouse input on the schematic
CHIP-8	A complete VM with a display, keypad, timers, and per-instance ROM selection
Z80	A Z80 computer on real EPROM, RAM and glue logic, with a 6850 ACIA, running NASCOM BASIC
Optional modules	UART and third-party control helpers

Documentation

• Using OpenVSM
• Building from source
• Lua graphics API
• Lua v0.7 compatibility
• Developer guide

OpenVSM v0.7 uses Lua 5.4 and builds as a 32-bit Windows DLL with C++20 and MSVC. It is licensed under GPL-2.0-or-later.