.

projects/04/fill/Fill.asm

@@ -0,0 +1,97 @@
+@END //check if button is pressed
+0;JMP
+
+(BLACK)
+//start= 16384 the start of the screen memory
+@SCREEN
+D=A
+@start
+M=D
+
+//n=8,192 this is the memory for the display =addreass of the keyboard - address of the screen
+@8192
+D=A
+@n
+M=D
+
+//i=0 this is the index for each group of pixels
+@i
+M=0
+
+(LOOP1)
+//if i==n goto end
+@i
+D=M
+@n
+D=D-M
+@END
+D;JEQ
+
+//start+1=-1 set each group of pixels to -1 which is = 111111111111
+@start
+D=M
+@i
+A=D+M
+M=-1
+
+// increment i by 1
+@i
+M=M+1
+
+// go back to the start of the loop
+@LOOP1
+0;JMP
+
+(WHITE)
+//start= 16384 the start of the screen memory
+@SCREEN
+D=A
+@start
+M=D
+
+//n=8,192 this is the memory for the display =addreass of the keyboard - address of the screen
+@8192
+D=A
+@n
+M=D
+
+//i=0 this is the index for each group of pixels
+@i
+M=0
+
+(LOOP2)
+//if i==n goto end
+@i
+D=M
+@n
+D=D-M
+@END
+D;JEQ
+
+//start+1=-1 set each group of pixels to 0 which is = 00000000
+@start
+D=M
+@i
+A=D+M
+M=0
+
+// increment i by 1
+@i
+M=M+1
+
+// go back to the start of the loop
+@LOOP2
+0;JMP
+
+//check if button is pressed
+(END)
+@KBD
+D=M
+@WHITE
+D;JEQ
+@KBD
+D=M
+@BLACK
+D;JNE
+@END
+0;JMP

projects/04/fill/Fill.tst

@@ -0,0 +1,11 @@
+// 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/Fill.tst
+
+load Fill.asm;
+echo "Make sure that 'No Animation' is selected. Then, select the keyboard, press any key for some time, and inspect the screen.";
+
+repeat {
+  ticktock;
+}

projects/04/fill/FillAutomatic.cmp

@@ -0,0 +1,4 @@
+|RAM[16384]|RAM[17648]|RAM[18349]|RAM[19444]|RAM[20771]|RAM[21031]|RAM[22596]|RAM[23754]|RAM[24575]|
+|       0  |       0  |       0  |       0  |       0  |       0  |       0  |       0  |       0  |
+|      -1  |      -1  |      -1  |      -1  |      -1  |      -1  |      -1  |      -1  |      -1  |
+|       0  |       0  |       0  |       0  |       0  |       0  |       0  |       0  |       0  |

projects/04/fill/FillAutomatic.tst

@@ -0,0 +1,37 @@
+// 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/FillAutomatic
+
+// This script can be used to test the Fill program automatically, 
+// rather than interactively. Specifically, the script sets the keyboard
+// memory map (RAM[24576]) to 0, 1, and then again to 0. This simulates the 
+// acts of leaving the keyboard untouched, pressing some key, and then releasing
+// the key. After each on of these simulated events, the script outputs the values
+// of some selected registers from the screen memory map (RAM[16384]-RAM[24576]).
+// This is done in order to test that these registers are set to 000...0 or 111....1, 
+// as mandated by how the Fill program should react to the keyboard events.
+
+load Fill.asm,
+output-file FillAutomatic.out,
+compare-to FillAutomatic.cmp,
+output-list RAM[16384]%D2.6.2 RAM[17648]%D2.6.2 RAM[18349]%D2.6.2 RAM[19444]%D2.6.2 RAM[20771]%D2.6.2 RAM[21031]%D2.6.2 RAM[22596]%D2.6.2 RAM[23754]%D2.6.2 RAM[24575]%D2.6.2;
+
+set RAM[24576] 0,    // the keyboard is untouched
+repeat 1000000 {
+  ticktock;
+}
+output;              // test that the screen is white
+
+set RAM[24576] 1,    // a keyboard key is pressed
+repeat 1000000 {
+  ticktock;
+}
+output;              // test that the screen is black
+
+set RAM[24576] 0,    // they keyboard in untouched
+repeat 1000000 {
+  ticktock;
+}
+output;              // test that the screen is white
+