updated print with new functions

resources/dsa/lib/print.dsa

@@ -13,11 +13,27 @@
 // usage for reset:
 //      push pcx
 //      jmp print::reset
+//
+// usage for clear:
+//      push pcx
+//      jmp print::clear
+//
+// usage for print_byte:
+//      push (register containing byte)
+//      push pcx
+//      jmp print::print_byte
+//
+// usage for print_word:
+//      push (register containing word)
+//      push pcx
+//      jmp print::print_word
+//
 
 dw display: 0x20000
 dw current: 0x20000
 
-// prints the given text to the screen.
+// ------------------------------------------
+// prints the string at addr(arg[0]) to the screen.
 print:
     push bpr
     mov spr, bpr
@@ -25,7 +41,7 @@ print:
     ldw bpr, rg0, 8
     ldw current, rg1
 
-print_loop:
+_print_loop:
 	ldb rg0, acc
 	stb acc, rg1
 
@@ -33,24 +49,47 @@ print_loop:
 	addi rg1, 1
 
     cmp acc, zero
-	jne print_loop
-    jmp end
+	jne _print_loop
+    jmp _end
 
-// return
-end:
-    stw rg1, current
-	
-    mov bpr, spr
-    pop bpr
-    return
+// ------------------------------------------
+// prints the value of arg[0] to the screen.
+print_word:
+    // initialise
+    push bpr
+    mov spr, bpr
 
-// resets the cursor position on the screen
+    // load byte into acc
+    ldw bpr, rg0, 8
+    ldw current, rg1
+
+    stw rg0, rg1
+    addi rg1, 4
+    jmp _end
+
+// ------------------------------------------
+// prints the last byte of arg[0] to the screen. 
+print_byte:
+    push bpr
+    mov spr, bpr
+
+    ldw bpr, rg0, 8
+    ldw current, rg1
+
+    stb rg0, rg1
+    addi rg1, 1
+    jmp _end
+
+// ------------------------------------------
+// resets the cursor position on the screen to 0x20000. (0,0)
 reset:
     push bpr
     mov spr, bpr
     ldw display, rg1
-    jmp end
+    jmp _end
 
+// ------------------------------------------
+// clears the screen
 clear:
     push bpr
     mov spr, bpr
@@ -58,10 +97,19 @@ clear:
     lli 500 rg0
     ldw display, rg1
 
-clear_loop:
+_clear_loop:
     dec rg0
     stw zero, rg1
     addi rg1, 4
     cmp rg0, zero
-    jgt clear_loop
-    jmp end
+    jgt _clear_loop
+    jmp _end
+
+// ------------------------------------------
+// return
+_end:
+    stw rg1, current
+	
+    mov bpr, spr
+    pop bpr
+    return

resources/dsa/test.dsa

@@ -9,10 +9,12 @@ init:
 	mov bpr, spr
 
 start:
-	lwi string, rg1
+	// string, rg1
+	lli 87, rg1
 
 	push rg1
-	call print::print
+
+	call print::print_byte
 	pop rg1
 	
 	hlt