From 73e7beb441692ec5e3bf2f2886cd800ae87c23ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Sun, 1 Aug 2021 16:39:06 +0300
Subject: [PATCH] =?UTF-8?q?=5F=5F0a98=20=E2=86=92=20last=5Fvalid=5Faddress?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 edlin.asm | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/edlin.asm b/edlin.asm
index 6e23bde..e4a4830 100644
--- a/edlin.asm
+++ b/edlin.asm
@@ -218,7 +218,7 @@ setup_file_parameters: ; 01ec
 
 	mov cx, [psp_segment_size]
 	dec cx
-	mov [__0a98], cx
+	mov [last_valid_address], cx
 
 	test byte [new_file_flag], 0xff
 	jnz initialize_editor
@@ -457,7 +457,7 @@ __0388:
 	mov ah, sys_set_dta
 	int 0x21
 
-	mov cx, [__0a98]
+	mov cx, [last_valid_address]
 	subw r_cx, r_dx
 	jz _trampoline_oom_1
 
@@ -494,7 +494,8 @@ __03ca:
 
 	std
 	dec di
-	mov cx, [__0a98]
+	; TODO: Why are we using last valid address as our loop counter?
+	mov cx, [last_valid_address]
 	repne scasb
 	inc di
 	inc di
@@ -1132,7 +1133,7 @@ __07d7:
 	mov ax, [__0a9a]
 	subw r_ax, r_dx
 	addw r_ax, r_cx
-	cmp ax, [__0a98]
+	cmp ax, [last_valid_address]
 	jnb oom
 
 	xchg ax, [__0a9a]
@@ -1183,7 +1184,7 @@ __082a:
 	movw r_si, r_cx
 	subw r_cx, r_di
 	inc cx
-	mov di, [__0a98]
+	mov di, [last_valid_address]
 
 	std
 	rep movsb
@@ -1240,7 +1241,7 @@ __088b:
 	mov di, [__0a92]
 	movw r_si, r_bp
 	inc si
-	mov cx, [__0a98]
+	mov cx, [last_valid_address]
 	subw r_cx, r_bp
 	rep movsb
 	dec di
@@ -1377,7 +1378,7 @@ __0a92 resw 1
 
 __0a94 resw 1
 __0a96 resw 1
-__0a98 resw 1
+last_valid_address resw 1 ; 0a98
 
 __0a9a resw 1