Implement console IO

io.asm

@@ -27,19 +27,19 @@ org 0
 
 ; Jump table
 jmp init ; 0000
-jmp status ; 0003
-jmp getch ; 0006
-jmp putch ; 0009
+jmp near ptr status ; 0003
+jmp near ptr getch ; 0006
+jmp near ptr putch ; 0009
 jmp unimplemented ; 000c Output to printer
 jmp unimplemented ; 000f Serial read
 jmp unimplemented ; 0012 Serial write
-jmp diskread ; 0015
+jmp near ptr diskread ; 0015
 jmp diskwrite ; 0018
 jmp near ptr diskchange ; 001b
 jmp setdate ; 001e
 jmp settime ; 0021
 jmp gettime ; 0024
-jmp flush ; 0027
+jmp near ptr flush ; 0027
 jmp near ptr mapdev ; 002a
 
 init:
@@ -98,23 +98,33 @@ init:
 ;  al = character if any
 ;  zf = there were no characters
 status proc far
+	push bx
 	push ax
-	mov ax, 0e00h + 's'
-	int 10h
+	mov ah, 1
+	int 16h
+	mov bl, al
 	pop ax
-	call far_caller
-	; TODO: Implement
-	xor ax, ax
-	test ax, ax
+	mov al, bl
+	pop bx
 	ret
 status endp
 
-getch:
-	mov al, 'g'
-	jmp error
+; OUT:
+;  al = character
+getch proc far
+	push bx
+	push ax
+	xor ah, ah
+	int 16h
+	mov bl, al
+	pop ax
+	mov al, bl
+	pop bx
+	ret
+getch endp
 
 ; IN:
-;  ax = character
+;  al = character
 putch proc far
 	push ax
 	mov ah, 0eh
@@ -290,17 +300,27 @@ settime:
 gettime:
 	mov al, 'T'
 	jmp error
-flush:
-	mov al, 'f'
-	jmp error
 
-mapdev proc far
+flush proc far
 	push ax
-	mov ax, 0e00h + 'm'
-	int 10h
+
+	flush_loop:
+		mov ah, 1
+		int 16h
+		jz flush_ret
+
+		xor ah, ah
+		int 16h
+		jmp flush_loop
+
+	flush_ret:
 	pop ax
-	call far_caller
-	; TODO: Figure out if this does anything?
+	ret
+flush endp
+
+mapdev proc far
+	; TODO: Implement
+	xor al, al
 	ret
 mapdev endp