From 4b385cf8f08825b01037d4fb94fa4723d94f30c7 Mon Sep 17 00:00:00 2001
From: Tibo Ulens <ulens.tibo@gmail.com>
Date: Fri, 8 Oct 2021 13:58:38 +0200
Subject: [PATCH] inline read_duration function

---
 messages.asm | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/messages.asm b/messages.asm
index cde24a9..6792af4 100644
--- a/messages.asm
+++ b/messages.asm
@@ -158,9 +158,16 @@ newline:
 ;; - bx
 ;; - cx
 beep:
-	call    read_duration	; get duration from keyboard (in al)
+	;; Read duration (0-16 supported)
+	mov ah, 0x00	; read keypress
+	int 0x16
+	;; Read ASCII character is in al
+	sub al, 'a' 	; normalise (a=0, b=1, c=...)
+
+	;; interrupt 0x16, ah=0 returns the read scancode in ah
+	;; so ah must be reset
 	mov     ah, 0
-	push    ax		; store on stack
+	push    ax	; store on stack
 
 	;; move 182 (0b10 11 011 0) into al
 	;; bit 7-6 = channel select (2, PC speaker)
@@ -299,15 +306,15 @@ readbyte:
 ;;
 ;; CLOBBERS
 ;; - ax
-read_duration:
-	;; Read duration (0-16 supported)
-	mov ah, 0x00	; read keypress
-	int 0x16
-
-	;; Read character is in al
-	sub al, 'a' 	; normalise
-
-	ret
+;read_duration:
+;	;; Read duration (0-16 supported)
+;	mov ah, 0x00	; read keypress
+;	int 0x16
+;
+;	;; Read character is in al
+;	sub al, 'a' 	; normalise
+;
+;	ret
 
 ;; Variable to store color mode information for writing to the screen
 color_mode: db 0x02