diff --git a/src/ui.attract.shr.a b/src/ui.attract.shr.a
index ca6ff4339..fddc6a54c 100644
--- a/src/ui.attract.shr.a
+++ b/src/ui.attract.shr.a
@@ -98,7 +98,7 @@ BlankSHR
          jsr   Home
 
          lda   NEWVIDEO              ; set GS NEWVIDEO mode to turn on linearize
-         ora   #$40
+         ora   #%01000000
          sta   NEWVIDEO
 
          sta   WRITEAUXMEM           ; writes go to auxmem
@@ -114,7 +114,7 @@ BlankSHR
          sta   WRITEMAINMEM          ; writes go to main memory
 
          lda   NEWVIDEO              ; set GS NEWVIDEO mode to turn on SHR mode
-         ora   #$81
+         ora   #%10000001
          sta   NEWVIDEO
 
          rts
diff --git a/src/ui.common.a b/src/ui.common.a
index 56b06357b..6b6f9f394 100644
--- a/src/ui.common.a
+++ b/src/ui.common.a
@@ -46,8 +46,11 @@ Home
          and   #SUPPORTS_SHR
          beq   @noSHR
          lda   NEWVIDEO
-         and   #$3F
-         sta   NEWVIDEO              ; get out of SHR mode and linear mode
+         and   #%00011111            ; bit 7 = 0 -> IIgs Apple II-compatible video modes
+                                     ; bit 6 = 0 -> IIgs 128K memory map is the same as the Apple IIe
+                                     ; bit 5 = 0 -> IIgs DHGR is color, not monochrome
+                                     ; bits 0-4 unchanged
+         sta   NEWVIDEO
          lda   #$F0
          sta   TBCOLOR               ; white text on black background
          lda   #$00