The Costa GUI

Costa is a graphical user interface (GUI), designed to run on top of the command line as a shell.

The low system requirements make Costa especially useful for older machines, which are also the machines that typically run the MS-DOS operating system.

System requirements

Costa is designed for MS-DOS, but tested with PC-DOS, DR-DOS, FreeDOS, Novell DR Multiuser DOS and DOSBox as well. In theory it should run on any IBM compatible system with:

• A 286 or better CPU (386 recommended)
• EGA (256KB or more VRAM required) or VGA graphics (any VGA compatible card should do)
• A recommended minimum of 200 KB available memory while running Costa. When running external programs or games, Costa will exit first and then reload after, taking no memory from your other programs.
• MS-DOS 4.0 or newer, or a compatible operating system

Although not required, a 386 or better CPU is recommended, as well as disk caching software (SmartDrive or similar) when running on older machines. Costa uses the path defined in the TEMP environment variable in AUTOEXEC.BAT for temporary file storage, so it is possible to use a RAM disk if desired. If TEMP is not defined, Costa will use the path where it is located.

Further information

See the included documentation for more information, or visit the homepage of Costa at http://costa.jacobpalm.dk

Icons and themes always welcome!

If you have made any icons you would like to see included with Costa, or perhaps a nifty theme, feel free to drop me a message. I am always looking to add more to Costa, and credit will of course be given!

Using this code

When opening project files (.MAK), use the /L parameter for all project files like so:

VBDOS.EXE DESKTOP.MAK /L

This will cause VBDOS to load the libraries neccesary for Costa to work. If you get an error relating to "CALL ABSOLUTE" or "CALL INTERRUPT", you have probably not used this parameter when starting VBDOS.

The source code and build script assume the following:

• That the source code has been extracted/cloned to C:\COSTA (this path is only required for development, once built Costa will run from any path)
• That Visual Basic for DOS is installed to C:\VBDOS, in a flat structure - that is, all files placed in the folder directly, including libraries and include files

Building Costa

To build Costa, run the build script from the command line:

_BUILD.BAT

This will compile all modules to object files, and call the linker for each individual executable. In the source folder, a .LNK file exists for each executable, with parameters for the linker. These can be modified as needed, following the standard syntax for Microsofts Segmented Executable Linker.

When compiling directly from the IDE, make sure to turn on run-time error checking, as well as 286 optimizations.