diff options
| author | Yuchen Pei <me@ypei.me> | 2018-01-20 15:41:49 +0100 |
|---|---|---|
| committer | Yuchen Pei <me@ypei.me> | 2018-01-20 15:41:49 +0100 |
| commit | d3a0cc3a8ba6dfeb64d3faeffdeb6845b60e5840 (patch) | |
| tree | d58df9ec2480e2a9ec6240f9c797f83d1a0b1056 /asms/Fill.asm | |
| parent | 3571f998b28fbc8d9250ba04c983935f10a16c15 (diff) | |
rearranged the dir for github
- removed tools and pdfs
- rearranged the projects dirs
- added md files
- other minor changes
Diffstat (limited to 'asms/Fill.asm')
| -rw-r--r-- | asms/Fill.asm | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/asms/Fill.asm b/asms/Fill.asm new file mode 100644 index 0000000..16d63e2 --- /dev/null +++ b/asms/Fill.asm @@ -0,0 +1,76 @@ +// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/04/Fill.asm
+
+// Runs an infinite loop that listens to the keyboard input.
+// When a key is pressed (any key), the program blackens the screen,
+// i.e. writes "black" in every pixel;
+// the screen should remain fully black as long as the key is pressed.
+// When no key is pressed, the program clears the screen, i.e. writes
+// "white" in every pixel;
+// the screen should remain fully clear as long as no key is pressed.
+
+// Put your code here.
+
+(BEGIN)
+@KBD
+D=M
+
+@BLACK
+D;JNE
+
+@WHITE
+0;JMP
+
+(BLACK)
+@8191
+D=A
+@i
+M=D
+
+(LOOPB)
+@i
+D=M
+@j
+M=D
+@SCREEN
+D=A
+@j
+M=M+D
+A=M
+M=-1
+@i
+M=M-1
+D=M
+@LOOPB
+D+1;JGT
+
+@BEGIN
+0;JMP
+
+(WHITE)
+@8191
+D=A
+@i
+M=D
+
+(LOOPW)
+@i
+D=M
+@j
+M=D
+@SCREEN
+D=A
+@j
+M=M+D
+A=M
+M=0
+@i
+M=M-1
+D=M
+@LOOPW
+D+1;JGT
+
+@BEGIN
+0;JMP
|