Screen Display Module M15.2 Sections 9.5, 13.1, 13.2

Screen Display Basic Screen Output –DOS Character Output –Set Cursor –String Output Raster Scan Displays The Video RAM

Screen Output

Print string on bottom line of screen Use /MA to enter string at address END STRING WITH $ SIGN

Program to display Hello on bottom line

Screen Display Basic Screen Output –DOS Character Output –Set Cursor –String Output Raster Scan Displays The Video RAM

Raster Scan Displays Electron beam CRT

Raster Scan Characters 9 14

Character generator Shift register Video signal Row select T H E Character line 1 (40 words or 80 bytes) Character line 2 (40 words or 80 bytes) even addresses odd addresses

Attribute Byte BLIR G B Foreground Intensity bit 0 = normal intensity 1 = high intensity Blinking bit 0 = not blinking 1 = foreground blinking Background

Screen Display Basic Screen Output –DOS Character Output –Set Cursor –String Output Raster Scan Displays The Video RAM

Video RAM Segment Addresses CGA, EGA, VGA

Video RAM - 40 columns

Video RAM - 80 columns

Video Ram Segment at $B800