| #include <stdio.h> #include <conio.h> #include <dos.h> #include <mem.h> #define _M_CO80 0x3 #define _M_VESA_320x200x256 0x13 #define _M_VESA_640x480x256 0x101 #define _M_VESA_800x600x256 0x103 #define _M_VESA_1024x768x256 0x105 #define FALSE 0 #define TRUE 1 typedef unsigned char BYTE; typedef unsigned short BOOL; struct TVESAInfo { char VESA_signature[4]; /* 'VESA' 4 byte signature */ short VESA_version; /* VBE version number */ char *OEM_string_ptr; /* Pointer to OEM string */ unsigned int capabilities; /* Capabilities of video card */ unsigned short *video_mode_ptr; /* Pointer to supported modes */ short total_memory; /* Number of 64kb memory blocks */ /* VBE 2.0 extension information */ short OEM_software_rev; /* OEM Software revision number */ char *OEM_vendor_name_ptr; /* Pointer to Vendor Name string */ char *OEM_product_name_ptr; /* Pointer to Product Name string */ char *OEM_product_rev_ptr; /* Pointer to Product Revision str */ char reserved[222]; /* Pad to 256 byte block size */ char OEM_data[256]; /* Scratch pad for OEM data */ }; struct TVESAModeInfo { short mode_attributes; /* Mode attributes */ char wina_attributes; /* Window A attributes */ char winb_attributes; /* Window B attributes */ short win_granularity; /* Window granularity in k */ short win_size; /* Window size in k */ unsigned short wina_segment; /* Window A segment */ unsigned short winb_segment; /* Window B segment */ void *win_func_ptr; /* Pointer to window function */ short bytes_per_scan_line; /* Bytes per scanline */ short x_resolution; /* Horizontal resolution */ short y_resolution; /* Vertical resolution */ char x_char_size; /* Character cell width */ char y_char_size; /* Character cell height */ char number_of_planes; /* Number of memory planes */ char bit_per_pixel; /* Bits per pixel */ char number_of_banks; /* Number of CGA style banks */ char memory_model; /* Memory model type */ char bank_size; /* Size of CGA style banks */ char number_of_image_pages; /* Number of images pages */ char res1; /* Reserved */ char red_mask_size; /* Size of direct color red mask */ char red_field_position; /* Bit posn of lsb of red mask */ char green_mask_size; /* Size of direct color green mask */ char green_field_position; /* Bit posn of lsb of green mask */ char blue_mask_size; /* Size of direct color blue mask */ char blue_field_position; /* Bit posn of lsb of blue mask */ char rsvd_mask_size; /* Size of direct color res mask */ char rsvd_field_position; /* Bit posn of lsb of res mask */ char direct_color_mode_info; /* Direct color mode attributes */ /* VBE 2.0 extensions information */ unsigned int phys_base_ptr; /* Physical address for linear buf */ unsigned int off_screen_mem_offset; /* Pointer to start of offscreen mem*/ short off_screen_mem_size; /* Amount of offscreen mem in 1K's */ char res2[206]; /* Pad to 256 byte block size */ }; TVESAInfo VESAInfo; TVESAModeInfo VESAModeInfo; BYTE *ScreenPtr = (BYTE *)MK_FP( 0xA000, 0x0000 ); int MAXX = 0; int MAXY = 0; int BANK_SHIFT = 0; BOOL CheckVESABIOS( ) { struct REGPACK reg; memset( ®, 0, sizeof( reg )); reg.r_ax = 0x4F00; reg.r_es = FP_SEG( &VESAInfo ); reg.r_di = FP_OFF( &VESAInfo ); intr( 0x10, ® ); if(( reg.r_ax == 0x4F ) && !memicmp( VESAInfo.VESA_signature, "VESA", 4 )) { return TRUE; } return FALSE; } BOOL CheckVESAMode( unsigned short mode ) { struct REGPACK reg; memset( ®, 0, sizeof( reg )); reg.r_ax = 0x4F01; reg.r_cx = mode; reg.r_es = FP_SEG( &VESAModeInfo ); reg.r_di = FP_OFF( &VESAModeInfo ); intr( 0x10, ® ); if( reg.r_ax == 0x4F ) { MAXX = VESAModeInfo.x_resolution; MAXY = VESAModeInfo.y_resolution; BANK_SHIFT = (VESAModeInfo.win_granularity == 64) ? 16:12; return TRUE; } return FALSE; } void SetVESAMode( unsigned short mode ) { union REGS regs; if( mode < 0x100 ) { regs.x.ax = mode; } else { regs.x.ax = 0x4F02; regs.x.bx = mode; } int86( 0x10, ®s, ®s ); } void SelectBank( unsigned short id ) { union REGS regs; regs.x.ax = 0x4F05; regs.x.bx = 0; regs.x.dx = id; int86(0x10, ®s, ®s); regs.x.ax = 0x4F05; regs.x.bx = 1; regs.x.dx = id; int86(0x10, ®s, ®s); } void CloseVESAMode( ) { SetVESAMode( _M_CO80 ); } void PutPixel( long x, long y, BYTE color ) { unsigned long pos = (y * MAXX) + x; unsigned short bank = pos >> BANK_SHIFT; pos -= (bank << BANK_SHIFT); SelectBank( bank ); *(ScreenPtr + (unsigned short)pos) = color; } int main( ) { if( !CheckVESABIOS( )) { printf( "Not found VESA BIOS.\n" ); return 0; } if( !CheckVESAMode( _M_VESA_640x480x256 )) { printf( "This mode not support.\n" ); return 0; } SetVESAMode( _M_VESA_640x480x256 ); PutPixel( 0, 0, 15 ); PutPixel( MAXX-1, 0, 15 ); PutPixel( MAXX-1, MAXY-1, 15 ); PutPixel( 0, MAXY-1, 15 ); getch( ); CloseVESAMode( ); return 0; } |
