Lua for Watcom

This repository contains wmake style makefiles and patches to build Lua on Open Watcom 1.9 or later.

Initially, the goal of the project was to allow modern Lua scripts to be run on DOS systems in real mode. The project has since expanded to include all Open Watcom targets that don't require external dependencies to build. Additionally, the simple scripts originally part of Lua for Open Watcoms disk images made to test these ports have been made into its own repository, Lua Scripts. It includes several example and utility scripts that can be used on any Lua 5.4 interpreter, including Lua for Watcom.

Download

Pre-compiled binaries and floppy disk images are available on the Release page. These releases are built from a GitHub Action workflow.

Files

There are two zips available for download in each release; which one you should download depends on how you plan to use the software. Both zips contain binaries for all listed platforms. See Binary Native Targets and Binary Compatibility Matrix to determine which binary is right for your system.

Watcom Lua Executables

This zip contains all demo scripts and platform binaries as regular files. The zip is formatted with DOS headers and has 8.3 friendly names.

Watcom Lua floppy disk Images

This zip contains two floppy disk format images (.ima format) which are ready to be written to real disks for distributing to retro machines or opened by emulators directly. To save space on these disk images, binaries have been compressed by UPX where possible. When that is not possible, the binaries are compressed in a zip.

Disk Image	Description
LUA14D{1/2}.IMA	2 1.4MB 3½ floppy disk images that contains all the same files as executable zip
LUA160k{1/2/3}.IMA	3 160k 5¼ floppy disk images with subset of scripts with only the DOS binaries due to space limitations of this type of disk

System Requirements

Lua for Watcom binaries can run on a number of legacy systems as well as some modern ones. The exact memory requirements will depend on the complexity of the script you want to run.

Binary Native Targets

Since Open Watcom can produce binaries for several operating systems, each binary has been given a unique name to distinguish the native Operating System and Instruction Set Architecture it is intended for.

Binary Name	Native Operating System	Native Instruction Set Architecture
LUA16.EXE	Real mode DOS	8086
LUA21.EXE	OS/2 1.2	80286
LUA22.EXE	OS/2 2.0	80386
LUA4G.EXE	DOS4GW extender	80386
LUANT.EXE	Windows 95	80386
LUAUX.ELF	Linux 1.2.13	80386

Binary Compatibility Matrix

Some operating systems can run binaries intended for another out of the box. In most cases, the operating system is newer and has higher hardware requirements.

Operating System	Instruction Set Architecture	LUA16	LUA21	LUA22	LUA4G	LUANT	LUAUX
DOS 2.x - 4.xWindows 1.x - 3.x	8086	Yes	No	No	No	No	No
DOS 5.x - 7.x	808680386SX	Yes	No	No	NoYes	No	No
OS2 1.0 - 1.1	80286	Yes	No	No	No	No	No
OS2 1.2 - 1.3	80286	Yes	Yes	No	No	No	No
OS2 2.x	80386SX	Yes	Yes	Yes	No	No	No
OS2 3.x	80386SX	Yes	Yes	Yes	Yes	No	No
OS2 4.x	80486SX	Yes	Yes	Yes	Yes	No	No
Linux 1.2.13+	80386SX	No	No	No	No	No	Yes
Windows 95	80386SX	Yes	No	No	Yes	Yes	No
Windows NT 4.0	80486SX	Yes	Yes	No	Yes	Yes	No
Windows 98	80486DX80486SX+80487SX	Yes	No	No	Yes	Yes	No
ReactOS 0.4.15	80586	Yes	No	No	No	Yes	No
Windows 2000 - ME	80586	No	No	No	No	Yes	No
Windows XP	80586x86_64	No	No	No	No	Yes	No

Software Dependencies

DOS

The 32-bit DOS4GW extender version of Lua for Watcom (LUA4G.EXE) requires DOS4GW.EXE to either be in the same directory or discoverable in a directory specified by the %PATH% environment variable.

The real-mode version of Lua for Watcom (LUA16.EXE) is completely self-contained and requires no extra files or directory structure. This version of Lua uses a large memory model, meaning Lua scripts are limited to 64k of memory.

Linux

The Linux version of Lua for Watcom (LUAUX.ELF) is completely self-contained and requires no libraries from a distribution, not even libc.

The Linux kernel itself needs support for running "i386" ELF binaries.

OS/2

OS/2 version 2.0 and later have 32-bit executable support and can run both the 16-bit (LUA21.EXE) and 32-bit (LUA22.EXE) OS/2 versions of Lua for Watcom.

OS/2 version 1.3 and earlier are 16-bit and can only run LUA21.EXE. DOSCALL1.DLL is required to run LUA21.EXE which is included in OS/2 v1.2 and later. This version of Lua uses a large memory model, meaning Lua scripts are limited to 64k of memory.

OS/2 version 1.1 and earlier should run LUA16.EXE in a DOS command prompt.

Windows

All the dependencies for the Windows version of Lua for Watcom (LUANT.EXE) ship in a minimal installation of Windows 95, there are effectively no dependencies.

Build

See the Build documentation.

Additionally, the GitHub Workflow can be studied to understand the release build workflow.

See also

Emulators and Compatibility Layers

As shown in the Binary Compatibility Matrix both LUANT.EXE and LUAUX.ELF are compatible with current versions of Windows and Linux operating systems respectively. An emulator should not be necessary to run these binaries on current Linux/Windows PCs with AMD/Intel processors.

If you want to run the DOS or OS/2 version on a modern PC or have a non-x86 processor in your machine, then any of the following software projects can be used to run the Lua binaries.

Name	Type	Repository	Comment
86BoxPCem	Full x86 PC Hardware Emulation	https://github.com/86Box/86Boxhttps://github.com/sarah-walker-pcem/pcem/	May require firmware binary blobs for emulated PC hardware.
DOSBox-X	DOS Environment Emulation	https://github.com/joncampbell123/dosbox-x	Only useful for running DOS applications like LUA16.EXE and LUA4G.EXE on non-DOS operating systems (including Windows versions after Windows 98). Not to be confused with DOSBox.
MiSTer FPGA	Full x86 PC Hardware Replication (Field Programmable Gate Array)	https://github.com/MiSTer-devel/ao486_MiSTerhttps://github.com/MiSTer-devel/PCXT_MiSTerhttps://github.com/MiSTer-devel/Wiki_MiSTer/wiki	Requires compatible field programmable gate array (FPGA) hardware.
Qemu	Processor Compatibility Layer & Hypervisor	https://gitlab.com/qemu-project/qemu	It might be possible set up qemu-i386 to run LUAUX.ELF on a non-x86 Linux system.Full virtual machines (qemu-i386-system & qemu-x86_64-system) are only recommended for running operating systems with guest driver support (Windows XP and later, Linux 2.6.26 and later etc...).
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