78 lines
1.5 KiB
NASM
78 lines
1.5 KiB
NASM
// This file is part of www.nand2tetris.org
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// and the book "The Elements of Computing Systems"
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// by Nisan and Schocken, MIT Press.
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// File name: projects/04/Fill.asm
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// Runs an infinite loop that listens to the keyboard input.
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// When a key is pressed (any key), the program blackens the screen,
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// i.e. writes "black" in every pixel;
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// the screen should remain fully black as long as the key is pressed.
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// When no key is pressed, the program clears the screen, i.e. writes
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// "white" in every pixel;
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// the screen should remain fully clear as long as no key is pressed.
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// Put your code here.
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@8192 // 32*256 --> 32 16er pro Zeile
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D=A
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@ENDPOS // in @16
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M=D
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(LOOP)
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@SCREEN //Screen-Einstiegsadresse
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D=A
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@ScreenStart //@SCREEN 16384 --> @17
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M=D
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@i //Zähler = 0 18
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M=0
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@KBD //24576
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D=M //Tastatureingabe ?
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@WEISS
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D; JEQ //WEISS WENN D == 0
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@SCHWARZ //SPRINGE ZU SCHWARZ
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D; JNE //WENN NICHT 0
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(SCHWARZ)
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@ENDPOS
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D=M
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@i
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D=D-M //ENDPOS -1 = 0 ? DANN ZU LOOP
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@LOOP
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D;JEQ
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@ScreenStart
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A=M
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M=-1 //SETZE -1 == SCHWARZ
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@i
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M=M+1 //i++
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@ScreenStart
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M=M+1
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@SCHWARZ
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0;JMP
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(WEISS)
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@ENDPOS
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D=M
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@i
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D=D-M //ENDPOS -1 = 0 ? DANN ZU LOOP
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@LOOP
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D;JEQ
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@ScreenStart
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A=M
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M=0 //SETZE 0 == WEISS
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@i
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M=M+1 //i++
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@ScreenStart
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M=M+1
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@WEISS
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0;JMP |