From 6f055a1ef919ecbfe3025f5d111d1bc87af278df Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Sun, 28 Nov 2021 15:46:29 -0500
Subject: [PATCH] update cursor save/cursor restore to also save the DECOM
 settings.  tested with vt100 (mame)

---
 vt.equ.S    | 1 +
 vt100.esc.S | 9 ++++++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/vt.equ.S b/vt.equ.S
index 87767a5..c8b30ad 100644
--- a/vt.equ.S
+++ b/vt.equ.S
@@ -82,6 +82,7 @@ mod		ds 2
 * saved cursor
 saved_x	ds 2
 saved_y	ds 2
+saved_decom ds 2
 
 	do *>256
 	err "too big"
diff --git a/vt100.esc.S b/vt100.esc.S
index 100ad39..5349ec7 100644
--- a/vt100.esc.S
+++ b/vt100.esc.S
@@ -134,21 +134,24 @@ vt100_esc ent
 
 
 esc_7 ; save cursor position, graphic rendition, and character set.
-
+* based on testing, DECOM is also saved/restored.
 	lda x
 	sta saved_x
 	lda y
 	sta saved_y
+	lda DECOM
+	sta saved_decom
 
 	rts
 esc_8 ; restore cursor position, graphic rendition, and character set.
 
-* TODO - how does this interact with DECOM?
-
 	lda saved_x
 	sta x
 	lda saved_y
 	sta y
+	lda saved_decom
+	sta DECOM
+
 	jmp recalc_cursor
 
 esc_eq ; enter alternate keypad mode