汇编源代码之图形显示方式屏幕的保存和恢复

核心提示：xor si,simov cx,1000hmov di,offset ram_bufferpush cspush dscldrep movsbxor di,di ;mov cx,80*25mov ax,57b1h ;填充背景，不然有乱字符cldrep stoswscr_retpop espop dsretss_mode

xor si,si

mov cx,1000h

mov di,offset ram_buffer

push cs

push ds

cld

rep movsb

xor di,di ;

mov cx,80*25

mov ax,57b1h ;填充背景，不然有乱字符

cld

rep stosw

scr_ret
　　pop es

pop ds

ret

ss_mode3:

call save_vram ;显示模式 3 保存显示 RAM

jmp short scr_ret

ss_mode7:

push 0b000h ;显示模式 7 保存显示 RAM

pop ds

call save_vram1

mov ax,3

int 10h

call restore_vram

jmp short scr_ret

SAVE_SCR ENDP

SAVE_VRAM PROC

push 0b800h ;把显示内存保存到自己的缓冲区

pop ds

save_vram1:

push cs

pop ds

xor si,si

mov di,offset ram_buffer

mov cx,2000h

cld

rep movsb

ret

SAVE_VRAM ENDP

RESTORE_VRAM PROC

push 0b800h ;恢复显示缓冲区内容

pop es

restore_vram1:

xor di,di

push cs

pop ds

mov si,offset ram_buffer

mov cx,2000h

cld

rep movsb

ret

RESTORE_VRAM ENDP

VGA_PAGE PROC

cmp vga_type,1

jnz other_vga1

cmp ah,1

jz vp_vesa2

cmp ah,2

jz vp_vesa1

mov ax,4f05h ;保存 VESA 显示卡状态

mov bx,0100h

int 10h

mov vga_win1,dx

mov ax,4f05h

mov bx,0101h

int 10h

mov vga_win2,dx

vp_vesa1:

mov ax,4f05h

xor bx,bx

xor dx,dx

int 10h

mov ax,4f05h

mov bx,0001h

xor dx,dx

int 10h

ret

vp_vesa2:

mov ax,4f05h

xor bx,bx

mov dx,vga_win1

int 10h

mov ax,4f05h

mov bx,0001h

mov dx,vga_win2
　　int 10h

ret

other_vga1:

cmp vga_type,3

jnz other_vga2

mov dx,3cdh

cmp ah,1

jz vp_tseng2

cmp ah,2

jz vp_tseng1

in al,dx

mov vga_win3,al

vp_tseng1:

xor al,al

out dx,al

ret

vp_tseng2:

mov al,vga_win3

out dx,al

vp_ret:

ret