First commit: Just managing the input

mine.asm

@@ -0,0 +1,95 @@
+org 100h                        ;specify .COM file
+
+start:
+        ; mov     al,13h          ;AX=0000 at program start
+        ; int     10h             ;init mode 13h
+        ; push    word 0A000h     ;Requires 80186 or higher to PUSH IMMED
+        ; pop     es              ;ES now points to mode 13h screen segment
+		; push    word 00000h     ;
+        ; pop     si
+
+mainloop:
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;This is where you do your mega-amazing tiny program.
+;Write 8-bit values to A000:0000 to draw some pixels.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+		
+		;Check for user wanting to leave by pressing ESC
+        in      al,60h                  ;read whatever is at keyboard port; looking for ESC which is #1
+		cmp     al,48h
+		je      upkey
+		cmp     al,4bh
+		je      leftkey
+        cmp     al,4dh
+        je      rightkey
+        cmp     al,50h
+        je      downkey
+		cmp     al,39h			
+		je      space
+        cmp     al,38h
+        je      lalt
+		mov     dword [lastkeypressed], 0h	;Reset the current key as it is not one we are checking
+        dec     al						;if ESC, AL now 0
+        jnz     mainloop        		;fall through if 0, jump otherwise
+        mov     al,03           		;AX=0000 due to mainloop exit condition
+        int     10h             		;Switch back to text mode as a convenience
+        ret                     		;.COM files can exit with RET
+
+upkey:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,31h
+        int     21h
+        jmp     mainloop
+
+leftkey:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,32h
+        int     21h
+        jmp     mainloop
+
+rightkey:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,33h
+        int     21h
+        jmp     mainloop
+
+downkey:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,34h
+        int     21h
+        jmp     mainloop
+
+space:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,39h
+        int     21h
+        jmp     mainloop
+
+lalt:
+		cmp     ax, [lastkeypressed]
+		je      mainloop
+		mov     [lastkeypressed], ax
+        mov     ah,02
+        mov     dl,38h
+        int     21h
+        jmp     mainloop
+
+;Data segment
+
+lastkeypressed:		db		0