From a64d01067d9aa038967130076761b597f2fb4736 Mon Sep 17 00:00:00 2001
From: pkali <pawel.kalinowski@gmail.com>
Date: Tue, 31 Jan 2023 16:35:02 -0500
Subject: [PATCH] vdl macro

---
 lib/MACRO.ASM | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lib/MACRO.ASM b/lib/MACRO.ASM
index 34aa3ba..477e2f5 100644
--- a/lib/MACRO.ASM
+++ b/lib/MACRO.ASM
@@ -51,6 +51,28 @@
          STX $0201
          STA NMIEN
          .ENDM
+;-------------------------------------
+        .MACRO VDL
+;   VDL #WORD
+;   Changes Display List addres
+; and sets width of the screen
+;    vdl dl,$01 - narrow screen (32 bytes)
+;    vdl dl,$02 - normal screen (40 bytes)
+;    vdl dl,$03 - wide screen   (48 bytes)
+;       (works only with system interrupts ON)
+
+         .if %0=2
+           lda dmactls
+           and #$fc
+           ora #%2
+           sta dmactls
+         .endif
+
+         LDA # <%1
+         STA DLPTRS
+         LDA # >%1
+         STA DLPTRS+1
+         .ENDM
 ;-------------------------------------
       .MACRO halt
 ?stop