Of course, there was only one screen under MS-DOS, but for example one could programming windows with the graphics library that came with QuickC 2.5 a little bit a la Windows. One could create a kind of Windows with it. Like this example (I have tried install MS-DOS 6.22 and Windows 3.1/95 in the VBox - it would not work):
That are four windows on top of each other and every window is/was separate. It's modelled with Photoshop now.
That is a part of the code . . .
Code:
/* 'kkuprzan.c' gehört zu KREDITEX.C */
/* Kurs einer jährlichen Annuitätenschuld mit Prozentannuitäten S.227 */
/* - 24. 9.1996 */
/*====================================================================*/
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <math.h>
#include <graph.h>
#define CURSOR_AUS 0x2000
#define CURSOR_NORMAL 0x0707
extern void kurs_jaehrl_prozent_annuschuld( void );
extern void kapital_effektiv_zins_menu( void );
void kurs_pannu( double nominal_zins, double effektiv_zins, double p_annu );
void kurs_jaehrl_prozent_annuschuld( void )
{
int vg_farbe, i, spalte;
int azeile, aspalte, ezeile, espalte;
unsigned int hg_farbe;
double effektiv_zins, nominal_zins, prozent_annu;
char puffer[64];
hg_farbe = _getbkcolor();
vg_farbe = _gettextcolor();
_gettextwindow( &azeile, &aspalte, &ezeile, &espalte );
//I think that was ist . . .
_setbkcolor( 15L );
_clearscreen( _GCLEARSCREEN );
_settextcolor( 14 );
_settextposition( 2, 8 );
_outtext( "Kurs einer Annuitaetenschuld mit jaehrlicher Zinszahlung und Tilgung" );
_settextposition( 3, 24 );
_outtext( "bei Tilgung durch Prozentannuitaet" );
. . .
}