cga.c File Reference

#include "includes.h"

Go to the source code of this file.

Functions

void CgaInit (void)

void CgaCursorSet (void)

void CgaScrollUp (void)

void CgaCharPut (U8 CharValue)

void CgaBackSpace (void)

void CgaScreenClean (void)

void CgaChangeLine (void)

Variables

CGA_CONTROL CgaCtrl

Function Documentation

void CgaBackSpace ( void )

Definition at line 58 of file cga.c.

00058                        {
00059     if(CgaCtrl.CursorPosition>=2) CgaCtrl.CursorPosition=CgaCtrl.CursorPosition-2;
00060     CgaByteWrite(CgaCtrl.CursorPosition,' ');
00061     CgaByteWrite(CgaCtrl.CursorPosition+1,CgaCtrl.CharacterAttribute);
00062 }

void CgaChangeLine ( void )

Definition at line 74 of file cga.c.

00074                         {
00075     U8 i;
00076     
00077     i=0;
00078     while(CgaCtrl.CursorPosition>160){
00079         CgaCtrl.CursorPosition=CgaCtrl.CursorPosition-160;
00080         i++;    
00081     }
00082     CgaCtrl.CursorPosition=(i+1)*160;
00083     if(CgaCtrl.CursorPosition==4000) CgaScrollUp(); 
00084 }

void CgaCharPut ( U8 CharValue )

Definition at line 46 of file cga.c.

00046                              {
00047     if((CharValue>=0x20)&&(CharValue<=0x7e)){
00048          CgaByteWrite(CgaCtrl.CursorPosition++,CharValue);
00049          CgaByteWrite(CgaCtrl.CursorPosition++,CgaCtrl.CharacterAttribute);
00050     }
00051     else{
00052          CgaByteWrite(CgaCtrl.CursorPosition++,'?');
00053          CgaByteWrite(CgaCtrl.CursorPosition++,CgaCtrl.CharacterAttribute);
00054     }
00055     if(CgaCtrl.CursorPosition==4000) CgaScrollUp();
00056 }

void CgaCursorSet ( void )

Definition at line 24 of file cga.c.

00024                        {
00025     OutByte(CGA_ADDRESS_PORT,CGA_CLLR);
00026     OutByte(CGA_DATA_PORT,((CgaCtrl.CursorPosition/2)&0xff));
00027     OutByte(CGA_ADDRESS_PORT,CGA_CLHR);
00028     OutByte(CGA_DATA_PORT,(((CgaCtrl.CursorPosition/2)>>8)&0xff));
00029 }

void CgaInit ( void )

Definition at line 14 of file cga.c.

00014                   {
00015     CgaCtrl.CursorPosition=0;
00016     CgaCtrl.CharacterAttribute=0x0f;
00017     CgaScreenClean();
00018     OutByte(CGA_ADDRESS_PORT,CGA_CLLR);
00019     OutByte(CGA_DATA_PORT,((CgaCtrl.CursorPosition/2)&0xff));
00020     OutByte(CGA_ADDRESS_PORT,CGA_CLHR);
00021     OutByte(CGA_DATA_PORT,(((CgaCtrl.CursorPosition/2)>>8)&0xff));
00022 }

void CgaScreenClean ( void )

Definition at line 64 of file cga.c.

00064                          {
00065     U32 i;
00066     
00067     for(i=0;i<4000;i=i+2){
00068         CgaByteWrite(i,' ');
00069         CgaByteWrite(i+1,CgaCtrl.CharacterAttribute);
00070     }
00071     CgaCtrl.CursorPosition=0;
00072 }

void CgaScrollUp ( void )

Definition at line 31 of file cga.c.

00031                       {
00032     U32 i;
00033     U8 ByteValue;
00034     
00035     for(i=0;i<3840;i++){
00036         ByteValue=CgaByteRead(i+160);
00037         CgaByteWrite(i,ByteValue);
00038     }
00039     for(i=3840;i<4000;i=i+2){
00040         CgaByteWrite(i,' ');
00041         CgaByteWrite(i+1,CgaCtrl.CharacterAttribute);
00042     }
00043     CgaCtrl.CursorPosition=3840;
00044 }

Variable Documentation

CGA_CONTROL CgaCtrl

Definition at line 12 of file cga.c.


Functions
void	CgaInit (void)
void	CgaCursorSet (void)
void	CgaScrollUp (void)
void	CgaCharPut (U8 CharValue)
void	CgaBackSpace (void)
void	CgaScreenClean (void)
void	CgaChangeLine (void)
Variables
CGA_CONTROL	CgaCtrl