From 0a5e80325a7b9ea9e1fbbb89d4debf833a0dc49b Mon Sep 17 00:00:00 2001
From: TomW <TomW@localhost>
Date: Thu, 13 Aug 2015 19:49:19 +0100
Subject: [PATCH] VGA RAMDAC does not update palette until all three elements
 are written. Fixes Windows 3.x EGA driver when run on a VGA card.

---
 src/vid_svga.c | 8 ++++----
 src/vid_svga.h | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/vid_svga.c b/src/vid_svga.c
index f718253..6c0b533 100644
--- a/src/vid_svga.c
+++ b/src/vid_svga.c
@@ -133,16 +133,16 @@ void svga_out(uint16_t addr, uint8_t val, void *p)
                 switch (svga->dac_pos)
                 {
                         case 0: 
-                        svga->vgapal[svga->dac_write].r = val & 63;
-                        svga->pallook[svga->dac_write] = makecol32(svga->vgapal[svga->dac_write].r * 4, svga->vgapal[svga->dac_write].g * 4, svga->vgapal[svga->dac_write].b * 4); 
+                        svga->dac_r = val & 63;
                         svga->dac_pos++; 
                         break;
                         case 1: 
-                        svga->vgapal[svga->dac_write].g = val & 63; 
-                        svga->pallook[svga->dac_write] = makecol32(svga->vgapal[svga->dac_write].r * 4, svga->vgapal[svga->dac_write].g * 4, svga->vgapal[svga->dac_write].b * 4); 
+                        svga->dac_g = val & 63;
                         svga->dac_pos++; 
                         break;
                         case 2: 
+                        svga->vgapal[svga->dac_write].r = svga->dac_r; 
+                        svga->vgapal[svga->dac_write].g = svga->dac_g;
                         svga->vgapal[svga->dac_write].b = val & 63; 
                         svga->pallook[svga->dac_write] = makecol32(svga->vgapal[svga->dac_write].r * 4, svga->vgapal[svga->dac_write].g * 4, svga->vgapal[svga->dac_write].b * 4); 
                         svga->dac_pos = 0; 
diff --git a/src/vid_svga.h b/src/vid_svga.h
index cd482c5..141a6b3 100644
--- a/src/vid_svga.h
+++ b/src/vid_svga.h
@@ -20,7 +20,8 @@ typedef struct svga_t
         
         uint8_t dac_mask, dac_status;
         int dac_read, dac_write, dac_pos;
-        
+        int dac_r, dac_g;
+                
         uint8_t cgastat;
         
         uint8_t plane_mask;