From e263c22bc310d82606b8ea942bfb5df5acd9848d Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 8 Jan 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-01-08

---
 pc/devvga.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pc/devvga.c b/pc/devvga.c
index 75726f5d3b1344db03b3ebde107b6bda7d146e5d..35e244a73febb7a81ccf624180440d2a34b474e0 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -325,6 +325,11 @@ vgawstat(Chan *c, char *dp)
 	error(Eperm);
 }
 
+uchar
+srin(int i) {
+	outb(SRX, i);
+	return inb(SR);
+}
 void
 genout(int reg, int val)
 {
@@ -649,7 +654,7 @@ atipage(int page)
 static void
 tridentpage(int page)
 {
-	srout(0x0e, page^0x02);
+	srout(0x0e, (srin(0xe)&0xf0) | page^0x02);
 }
 static void
 tsengpage(int page)