From 0d7d28dcfa08a3d161ca2bd1e774a7c28628a201 Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Fri, 18 Dec 2020 19:50:01 +0100
Subject: [PATCH] fixed 40/80 column screen detection in the monitor

---
 src/mon_m65/,imports_monitor.s |  1 +
 src/mon_m65/bsmon.s            | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/src/mon_m65/,imports_monitor.s b/src/mon_m65/,imports_monitor.s
index 49073c70..78a85e28 100644
--- a/src/mon_m65/,imports_monitor.s
+++ b/src/mon_m65/,imports_monitor.s
@@ -6,6 +6,7 @@
 
 ;; #ALIAS# SETMSG            = KERNAL_0.SETMSG
 ;; #ALIAS# STOP              = KERNAL_0.STOP
+;; #ALIAS# SCREEN            = KERNAL_0.SCREEN
 
 ;; #ALIAS# monitor_exit      = KERNAL_0.m65_shadow_BZP
 
diff --git a/src/mon_m65/bsmon.s b/src/mon_m65/bsmon.s
index 3a2cc2e6..b28dd9e9 100644
--- a/src/mon_m65/bsmon.s
+++ b/src/mon_m65/bsmon.s
@@ -466,6 +466,8 @@ Fetch
 Mon_Memory
 ; ********
 
+         JSR  Set_MODE_80
+
          JSR  Get_LAC           ; get 1st. parameter
          LDZ  #16               ; default row count
          BCS  @row              ; no address
@@ -564,6 +566,8 @@ Mon_Set_Register
 Mon_Set_Memory
 ; ************
 
+         JSR  Set_MODE_80
+
          JSR  Get_LAC           ; get 1st. parameter
          BCS  @exit
          JSR  LAC_To_LPC        ; Long_PC = row address
@@ -654,6 +658,8 @@ Dump_4_Chars
 Dump_Row
 ; ******
 
+         JSR  Set_MODE_80
+
          PHZ
          JSR  Print_CR
          LDA  #'>'
@@ -2805,3 +2811,30 @@ Mon_Help
          !pet 0
 
          JMP Main
+
+
+; *********
+Set_MODE_80
+; *********
+
+        ; Not too effective, but allows to retain more original code
+
+        PHP
+        PHA
+        PHX
+        PHY
+
+        JSR SCREEN
+        CPX #80
+        BEQ @1
+        LDA #$FF
+        +skip_2_bytes_trash_nvz
+@1      LDA #$00
+        STA MODE_80
+
+        PLY
+        PLX
+        PLA
+        PLP
+
+        RTS