/********************************************************************** * S O F T S C R C . C * **-------------------------------------------------------------------** * Task : Demonstrates soft scrolling on EGA & VGA cards. * **-------------------------------------------------------------------** * Author : Michael Tischer * * Developed on : 08/26/90 * * Last update : 02/21/92 * **-------------------------------------------------------------------** * (MICROSOFT C) * * Compilation : CL /AS /c /W0 softscrc.c * * LINK softscrc softscca; * **-------------------------------------------------------------------** * (BORLAND TURBO C) * * Compilation : Create a project file containing the following: * * softscrc.c * * softscca.obj * **-------------------------------------------------------------------** * Call : softscrc * **********************************************************************/ #include /* Add include files */ #include #include #include #ifdef __TURBOC__ /* Compiling with Turbo C? */ #define CLI() disable() #define STI() enable() #define outpw( p, w ) outport( p, w ) #ifndef inp #define outp( p, b ) outportb( p, b ) #define inp( p ) inportb( p ) #endif #else /* No --> QuickC 2.0 or MSC */ #include #define MK_FP(seg,ofs) ((void far *)\ (((unsigned long)(seg) << 16) | (ofs))) #define CLI() _disable() #define STI() _enable() #endif #define FAST 2 /* Speed constant for ShowScrlText() */ #define MEDIUM 1 #define SLOW 0 #define PCOLR 0x5E /* Yellow from lilac palette */ #define PCOLR1 0x5F /* White from lilac palette */ #define CWIDTH 8 /* Character width in pixels */ #define CHEIGHT 14 /* Character height in scan lines */ #define COLUMNS 216 /* Columns per row in video RAM */ #define BANDSIZE 10800 /* Band size */ #define BANDNUM 3 /* Number of bands */ #define MAXLEN 61 /* Maximum number of characters */ #define STARTR 5 /* Starting character row on screen */ #define CrtAttr 0x3C0 /* CRT attribute controller register */ #define CrtStatus 0x3da /* Status port */ #define CrtAdr 0x3d4 /* Monitor address port */ #define TRUE ( 0 == 0 ) #define FALSE ( 0 == 1 ) #define EGA 0 /* Card types */ #define VGA 1 #define NEITHERNOR 2 typedef unsigned char BYTE; /* Create a BYTE */ typedef unsigned int WORD; /* Create a WORD */ typedef BYTE BOOL; typedef WORD VRAM[BANDNUM][25][COLUMNS]; /* Video RAM definition */ typedef VRAM far *VPTR; /* FAR pointer to video RAM */ typedef BYTE FDEF[256][14]; /* Font array */ typedef FDEF far *TPTR; /* Pointer to font */ /*-- External functions ---------------------------------------------*/ extern void far * getfontptr( void ); /* Assembler function */ /*-- Global variables -----------------------------------------------*/ VPTR vp; /* Pointer to video RAM */ /********************************************************************** * SetOrigin : Specifies the visible part of video RAM for * * programming the video controller. * **-------------------------------------------------------------------** * Input : BAND = Number of band to be displayed (1-5) * * COLUMN, = Number of columns and rows displayed in the * * SCROW upper-left corner of the screen (origin=0/0) * * PIXX, = Pixel offsets * * PIXY * * Output : None * **********************************************************************/ void SetOrigin( BYTE band, BYTE column, BYTE scrow, BYTE pixx, BYTE pixy) { int offset; /* Offset of video RAM start */ offset = ( BANDSIZE >> 1) * band + scrow * COLUMNS + column; /*- Execute vertical rescan and wait for end -----------------------*/ while ( !(( inp(CrtStatus) & 8 ) == 8 )) ; while ( !(( inp(CrtStatus) & 8 ) == 0 )) ; /* Write offset for start of video RAM to registers 0CH and 0DH, */ /* after ensuring that next screen layout is valid */ CLI(); /* Disable interrupts */ outpw( CrtAdr, ( offset & 0xFF00 ) + 0x0c ); outpw( CrtAdr, ( (BYTE) offset << 8 ) + 0x0d ); STI(); /* Enable interrupts */ /*- While waiting for next rescan, write new pixel offset ----------*/ /*- and set up new starting address ----------*/ while ( !(( inp( CrtStatus ) & 8 ) == 8 )) ; /*- Write pixel offsets in register 08H or -----------------------*/ /*- register 13H of the attribute controller -----------------------*/ CLI(); /* Disable interrupts */ outpw( CrtAdr, ( pixy << 8 ) + 0x08 ); outp( CrtAttr, 0x13 | 0x20 ); outp( CrtAttr, pixx ); STI(); /* Enable interrupts */ } /********************************************************************** * PrintChar : Creates a character within the visible range of * * video RAM. * **-------------------------------------------------------------------** * Input : THECHAR = Character to be created * * BAND = Band number (0-4) * * COLUMN = Column in video RAM at which the column * * should begin * * Info : The character can be moved in the visible range of * * the screen by calling SmoothLeft. * * The character is created from a 14x8 matrix, based on * * the EGA/VGA ROM font. * **********************************************************************/ void PrintChar( char thechar, BYTE band, BYTE column ) { char ch; /* Character pixels */ BYTE i, k, /* Loop counter */ BMask; /* Bit mask for character design */ static TPTR fptr = (TPTR) 0; /* Pointer to ROM font */ if ( fptr == (TPTR) 0 ) /* Pointer to font already set? */ fptr = getfontptr(); /* No --> Get assembly language function */ /*- Generate character line by line --------------------------------*/ for ( i = 0; i < CHEIGHT; ++i ) { BMask = (*fptr)[thechar][i]; /* Get bit pattern for one line */ for ( k = 0; k < CWIDTH; ++k ) /* Set individual bits */ { ch = ( BMask & 128 ) ? 219 : 32; (*vp)[band][STARTR+i][column*CWIDTH+k] = (BYTE) ch+( PCOLR << 8 ); BMask <<= 1; /* Process next bit */ } } } /********************************************************************** * IsEgaVga : Determines whether an EGA or a VGA card is installed. * **-------------------------------------------------------------------** * Input : None * * Output : EGA, VGA or NEITHERNOR * **********************************************************************/ BYTE IsEgaVga( void ) { union REGS Regs; /* Processor registers for interrupt call */ Regs.x.ax = 0x1a00; /* Function 1AH applies to VGA only */ int86( 0x10, &Regs, &Regs ); if ( Regs.h.al == 0x1a ) /* Is the function available? */ return VGA; else { Regs.h.ah = 0x12; /* Call function 12H, */ Regs.h.bl = 0x10; /* sub-function 10H */ int86(0x10, &Regs, &Regs ); /* Call video BIOS */ return ( Regs.h.bl != 0x10 ) ? EGA : NEITHERNOR; } } /********************************************************************** * ShowScrlText : Scrolls text on the screen. * **-------------------------------------------------------------------** * Input : STEXT = String of text for scrolling * * SPEED = Scroll speed (SLOW, MEDIUM or FAST) * * VC = Video card type (EGA or VGA) * **********************************************************************/ void ShowScrlText( char * stext, BYTE speed, BYTE vc ) { int band, /* Current band */ column, /* Current column */ index, /* Index to string to be created */ len, /* Length of text to be displayed */ i, k, /* Loop counter */ pixx; /* Horizontal pan value */ WORD far *wptr; /* Pointer to video RAM loop */ union REGS Regs; /* Processor registers for interrupt call */ static BYTE steptable[2][3][10] = { { /* EGA step values */ { 0, 1, 2, 3, 4, 5, 6, 7, 255, 255 }, { 0, 2, 4, 6, 255, 255, 255, 255, 255, 255 }, { 0, 4, 255, 255, 255, 255, 255, 255, 255, 255 } }, { /* VGA step values */ { 8, 0, 1, 2, 3, 4, 5, 6, 7, 255 }, { 8, 2, 5, 255, 255, 255, 255, 255, 255, 255 }, { 8, 3, 255, 255, 255, 255, 255, 255, 255, 255 } } }; vp = MK_FP( 0xB800, 0x0000 ); /* Set pointer to video RAM */ /*- Fill entire video RAM with blank spaces ------------------------*/ for ( index = 0; index < BANDNUM; ++index ) for ( i = 0; i < 25; ++i ) for ( k = 0; k < COLUMNS; ++k ) (*vp)[index][ i ][ k ] = ( PCOLR << 8 ) + 32; /*- Draw horizontal bands ------------------------------------------*/ for ( k = 0; k < BANDNUM; ++k ) for ( i = 0; i < COLUMNS; ++i ) { (*vp)[ k ][ STARTR-2 ][ i ] = (BYTE) 'Í' + ( PCOLR1 << 8 ); (*vp)[ k ][ STARTR + CHEIGHT + 2][ i ] = (BYTE) 'Í' + ( PCOLR1 << 8 ); } /*- Remove blinking cursor from the screen -------------------------*/ Regs.h.ah = 0x02; /* Function number: Set cursor */ Regs.h.bh = 0; /* Screen page */ Regs.x.dx = 0; /* coordinates */ int86( 0x10, &Regs, &Regs ); /*- Set screen border color ----------------------------------------*/ Regs.h.ah = 0x10; /* Function number: Set border color */ Regs.h.al = 0x01; /* Sub-function number */ Regs.h.bh = PCOLR >> 4; /* Border color */ int86( 0x10, &Regs, &Regs ); /*- Place number of columns per row in video RAM from columns ------*/ outpw( CrtAdr, ( ( COLUMNS >> 1 ) << 8 ) + 0x13 ); /*-- Place scrolling text in video RAM -----------------------------*/ if ( ( len = strlen( stext ) ) > MAXLEN ) /* String too long? */ *(stext + ( len = MAXLEN )) = '\0'; /* Yes --> Truncate */ for ( column = band = index = 0; index < len; ) { PrintChar( *(stext+index++), band, column++ ); /* Draw characters */ if ( column >= COLUMNS / CWIDTH ) /* Band change? */ { /* Yes */ column = 0; /* Restart in column 1 */ ++band; /* Next band */ index -= 80 / CWIDTH; /* Character one page back */ } } /*-- Move scroll text from right to left on the screen ------------*/ for ( column = band = 0 , i = (len - ( 80 / CWIDTH )) * CWIDTH; i > 0; --i ) { for ( k = 0; ( pixx = steptable[vc][speed][k]) != 255 ; ++k ) SetOrigin( band, column, 0, pixx, 0 ); if ( ++column == COLUMNS - 80 ) /* Band change? */ { /* Yes */ column = 0; /* Restart in column 0 */ ++band; /* Increment band */ } } /*- Revert to 80 characters per row in video RAM -------------------*/ outpw( CrtAdr, ( 40 << 8 ) + 0x13 ); SetOrigin( 0, 0, 0, 8, 0 ); /* Revert to default */ /*- Return cursor to the screen ------------------------------------*/ Regs.h.ah = 0x02; /* Function number: Set cursor */ Regs.h.bh = 0; /* Screen page */ Regs.x.dx = 0; /* coordinates */ int86( 0x10, &Regs, &Regs ); /*- Reset border colors --------------------------------------------*/ Regs.h.ah = 0x10; /* Function number: Set border color */ Regs.h.al = 0x01; /* Sub-function number */ Regs.h.bh = 0; /* Black border */ int86( 0x10, &Regs, &Regs ); /*-- Clear screen --------------------------------------------------*/ for ( wptr = (WORD far *) vp, i = 80*25; i-- ; ) *wptr++ = 0x0720; } /*********************************************************************/ /** M A I N P R O G R A M **/ /*********************************************************************/ void main( void ) { BYTE vc; /* Get video card type */ if ( ( vc = IsEgaVga() ) == NEITHERNOR ) printf( "SOFTSCRC - (c) 1992 by Michael Tischer\n" \ "Warning: No EGA or VGA card found\n" ); else ShowScrlText( "++ PC Intern...........Published by Abacus ++" \ " ", FAST, vc ); }