Assembly Programming

1. COMPUTER ORGANIZATION
& ASSEMBLY LANGUAGE
LECTURE ON 10H WEEK 13 PRACTICAL
BY MUHAMMAD JAFER
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2. INT 10H
• Burned into ROM of BIOS
• Associated with monitor screen
• Perform different function based upon value in AH
• Function Performed are
• Clearing Screen
• Change the cursor position
• Change the screen color
• Draw line on screen
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3. MONITOR SCREEN IN TEXT MODE
• 80 columns & 25 rows
• 80 characters wide by 25 character long
• 80 column = 00 to 79
• 25 rows= 00 to 24
• First column is at 00,00
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4. CLEARING SCREEN
• AH=06
• AL=00
• BH=07
• CX=0000
• DH=24
• DL=79
• INT 10H
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5. SET CURSOR LOCATION
• AH=02
• BH=00
• DH=24
• DL=59
• INT 10H
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6. GET CURSOR LOCATION
• AH=03
• BH=00
• INT 10H
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7. VIDEO MODES
• AH=00
• AL=VIDEO MODE
• VIDEO MODE = TEXT MODE & RESOLUTION
• Attribute Byte = Associated with Each Character on Screen
• MONOCHROME
• Black & White
• D0 ~ D2 = Foreground Intensity
• D3= 1/0 High or Normal Intensity
• D4 ~ D6 = Background Intensity
• D7 = nonBlicking / Blicking Intensity
• CGA
• Color Graphics Adapter
• D0 ~ D2 = RGB Foreground
• D3= Foreground Intensity
• D4 ~ D6 = RGB Background
• D7 = nonBlicking / Blicking Intensity
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8. PIXEL RESOLUTIONS & COLOR
• Graphical Mode related to Pixel
• Two Important Things about Pixels
• Location
• Attribute
• Stored In Video RAM
• Increase in Pixel = Increase in Memory Required to store
• CGA = Max 16K bytes (Design)
• There are three modes of CGA
• Text mode of 80 * 25 Characters
• Graphical mode of 320 * 200 Resolution
• Graphical mode of 640 * 200 Resolution
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9. 80 * 25 CHARACTERS
• 2k bytes = 80 * 25
• Total 4k bytes
• 2k = locations
• 2k = attributes
• 4 pages of data supporting
• Each Page = 1 Screen
• 16 colors supported
• AL = 03 & AH = 00
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10. 320 * 200 RESOLUTION
• 6400 Pixels = 320 * 200
• 128 bits of Videos Ram
• 2 bits for Color
• 1 bits for Location
• 4 colors supported
• AL = 04 & AH = 00
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11. 640 * 200 RESOLUTION
• 12800 Pixels = 620 * 200
• 128 bits of Videos Ram
• 1 bits for Color
• 1 bits for Location
• Black & White supported
• AL = 06 & AH = 00
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12. PIXEL PROGRAMMING
• AH = OCH
• CX = X-Coordinate
• DX = Y-Coordinate
• BH = Page Number
• AL = Color
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13. PIXEL PROGRAMMING
• AH = OCH
• CX = X-Coordinate
• DX = Y-Coordinate
• BH = Page Number
• AL = Color
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14. CHAPTER REVIEW
• The x86 PC Assembly Language, Design &
Interfacing
• Chapter # 4
• BIOS INT 10H PROGRAMMING
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