diff --git a/src/vid_s3.c b/src/vid_s3.c
index 438e2ef..b6aa40f 100644
--- a/src/vid_s3.c
+++ b/src/vid_s3.c
@@ -798,7 +798,10 @@ void s3_out(uint16_t addr, uint8_t val, void *p)
                 
                 case 0x3C6: case 0x3C7: case 0x3C8: case 0x3C9:
 //                pclog("Write RAMDAC %04X %02X %04X:%04X\n", addr, val, CS, pc);
-                sdac_ramdac_out(addr, val, &s3->ramdac, svga);
+                if (s3->chip == S3_TRIO32 || s3->chip == S3_TRIO64)
+                        svga_out(addr, val, svga);
+                else
+                        sdac_ramdac_out(addr, val, &s3->ramdac, svga);
                 return;
 
                 case 0x3D4:
@@ -933,6 +936,8 @@ uint8_t s3_in(uint16_t addr, void *p)
                 
                 case 0x3c6: case 0x3c7: case 0x3c8: case 0x3c9:
 //                pclog("Read RAMDAC %04X  %04X:%04X\n", addr, CS, pc);
+                if (s3->chip == S3_TRIO32 || s3->chip == S3_TRIO64)
+                        return svga_in(addr, svga);
                 return sdac_ramdac_in(addr, &s3->ramdac, svga);
 
                 case 0x3d4: