VIO Tutorial (Hello, World)

This is a short tutorial on writing text to the console, the basics, and then with some color and cursor positioning.

All examples have been compiled with OpenWatcom.

VIO is short for Video Input/Output, and is the console interface to eCS.

The following is a hello, world application for the eCS VIO API.

#define INCL_VIO
#include <os2.h>

int main( int argc, char *argv[] )
{
	APIRET rc = VioWrtTTY( "Hello, VIO\n", // string to write
	                       11,             // lenght of string to write
	                       0 );            // VIO handle, must be 0
	return rc;
}

This can be compiled with OpenWatcom 1.3, as such: WCL386 vio.cpp, assuming the file name of vio.cpp.

Character Attributes

Lower Nibble: Character

Bit 0: Blue (0x01)
Bit 1: Green (0x02)
Bit 2: Red (0x04)
Bit 3: Intensity (0x08)

Higher Nibble: Background

Bit 4: Blue (0x10)
Bit 5: Green (0x20)
Bit 6: Red (0x40)
Bit 7: Blink/Intensity (0x80) (VioSetState)

Color Example

#define INCL_VIO
#include <os2.h>

int main( int argc, char *argv[] )
{
       char buffer[32] = {
	        'H', 12,       // intense red
		'e', 9,        // intense blue
	        'l', 10,       // intense green
               'l', 12,
               'o', 9,
               ',', 10,
               ' ', 0,
               'i', 12,
               'n', 9,
               ' ', 0,
               'c', 10,
               'o', 12,
               'l', 9,
               'o', 10,
               'r', 12,
               '!', 9 };

       APIRET rc = VioWrtCellStr( buffer,
                             32,         // Buffer length
                             3,          // Row, 3 to allow some scrolling
                             0,          // Column
                             0 );        // VioHandle, must be 0

       return rc;
}