From: Guillermo J. Rozas <edu/mit/csail/zurich/gjr>
Date: Wed, 30 Sep 1992 03:55:47 +0000 (+0000)
Subject: Improve the real-mode keyboard interrupt handler to eliminate some
X-Git-Tag: 20090517-FFI~8884
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=501ede9be4bb6a1b1924f9acb3d771e24d6cd44c;p=mit-scheme.git

Improve the real-mode keyboard interrupt handler to eliminate some
jumps.
---

diff --git a/v7/src/microcode/doskbutl.asm b/v7/src/microcode/doskbutl.asm
index 5c066a96f..c527911a6 100644
--- a/v7/src/microcode/doskbutl.asm
+++ b/v7/src/microcode/doskbutl.asm
@@ -1,6 +1,6 @@
 ;;; -*-Midas-*-
 ;;;
-;;;	$Id: doskbutl.asm,v 1.5 1992/09/06 16:24:10 jinx Exp $
+;;;	$Id: doskbutl.asm,v 1.6 1992/09/30 03:55:47 jinx Exp $
 ;;;
 ;;;	Copyright (c) 1992 Massachusetts Institute of Technology
 ;;;
@@ -168,33 +168,20 @@ kbd_isr:
 	push	bx
 	and	bx,3fh			; Drop fncn
 
+	push	si
+	mov	si,word ptr cs:shifted_table_offset
 	test	al,7h			; Ctrl or shift set?
-	jne	do_shifted
+	jne	do_fetch
+
+	mov	si,word ptr cs:caps_table_offset
 	test	al,40h			; CAPS set?
-	jne	do_caps
+	jne	do_fetch
 
-do_unshifted:
-	push	si
 	mov	si,word ptr cs:unshifted_table_offset
-	mov	bl,byte ptr cs:[bx+si]
-	pop	si
-	jmp	merge
 
-do_shifted:
-	push	si
-	mov	si,word ptr cs:shifted_table_offset
-	mov	bl,byte ptr cs:[bx+si]
-	pop	si
-	jmp	merge
-
-do_caps:
-	push	si
-	mov	si,word ptr cs:caps_table_offset
-	mov	bl,byte ptr cs:[bx+si]
+do_fetch:
+	mov	bl,byte ptr cs:[bx+si]	; Fetch translated byte.
 	pop	si
-;	jmp	merge
-
-merge:
 	cmp	bl,0			; No translation?
 	je	abort_translation
 	; bt	al,2h			; Control set?