Switching Around Your DOS Video Mode: The following is an assembler program which will set your system to video mode 03, which is the default MS-DOS video mode: MOV AX,0003h INT 10h INT 20h (Compiled into machine language, this program is 7 bytes. In hexadecimal, they are: B8 03 00 CD 10 CD 20) Modern programs shouldn't actually end with INT 20, so you should use this instead: MOV AX,0003h INT 10h MOV AX,4C00h INT 21h (Compiled into machine language, this program is 10 bytes. In hex, they are: B8 03 00 CD 10 B8 00 4C CD 21) In the first line, the number specifies what mode to change to. The first two digits must be 00 for this to work, but the last two specify the actual mode to switch to. Here are some values you can use instead of 03, along with their corresponding video modes: 00: 40x25 Black and White text (CGA,EGA,MCGA,VGA) 01: 40x25 16 color text (CGA,EGA,MCGA,VGA) 02: 80x25 16 shades of gray text (CGA,EGA,MCGA,VGA) 03: 80x25 16 color text (CGA,EGA,MCGA,VGA) 04: 320x200 4 color graphics (CGA,EGA,MCGA,VGA) 05: 320x200 4 color graphics (CGA,EGA,MCGA,VGA) 06: 640x200 B/W graphics (CGA,EGA,MCGA,VGA) 07: 80x25 Monochrome text (MDA,HERC,EGA,VGA) 08: 160x200 16 color graphics (PCjr) 09: 320x200 16 color graphics (PCjr) 0A: 640x200 4 color graphics (PCjr) 0D: 320x200 16 color graphics (EGA,VGA) 0E: 640x200 16 color graphics (EGA,VGA) 0F: 640x350 Monochrome graphics (EGA,VGA) 10: 640x350 16 color graphics (EGA or VGA with 128K) 640x350 4 color graphics (64K EGA) 11: 640x480 B/W graphics (MCGA,VGA) 12: 640x480 16 color graphics (VGA) 13: 320x200 256 color graphics (MCGA,VGA)