From 8476360e9f5f3737eb740e8faffdeece2e4847aa Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Mon, 24 Aug 2015 02:53:47 -0400
Subject: [PATCH] Fixed bugs in geos-cbm's dio_open().
* Trying to open an unused drive would leave a byte on the hardware stack.
* Too high device numbers weren't caught.
---
libsrc/geos-cbm/disk/dio_openclose.s | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/libsrc/geos-cbm/disk/dio_openclose.s b/libsrc/geos-cbm/disk/dio_openclose.s
index ec5aa8795..72e3e32e9 100644
--- a/libsrc/geos-cbm/disk/dio_openclose.s
+++ b/libsrc/geos-cbm/disk/dio_openclose.s
@@ -1,8 +1,8 @@
;
-; Maciej 'YTM/Elysium' Witkowiak
+; 2001-07-02, Maciej 'YTM/Elysium' Witkowiak
+; 2015-08-24, Greg King
;
; based on Atari version by Christian Groessler
-; 2.7.2001
;
; dhandle_t __fastcall__ dio_open (unsigned char device);
; unsigned char __fastcall__ dio_close (dhandle_t handle);
@@ -27,11 +27,13 @@ sectsizetab:
.code
_dio_open:
- pha
+ cmp #4
+ bcs _inv_drive
tax
lda driveType,x ; check if there's a device
beq _inv_drive
txa
+ pha
clc
adc #8 ; normalize devnum
sta curDevice