diff --git a/applecorn.po b/applecorn.po
index 893cc31..22b7713 100644
Binary files a/applecorn.po and b/applecorn.po differ
diff --git a/applecorn.s b/applecorn.s
index af32207..6da0007 100644
--- a/applecorn.s
+++ b/applecorn.s
@@ -95,6 +95,7 @@ RD80VID     EQU   $C01F
 
 TBCOLOR     EQU   $C022       ; GS-specific, used but commented out
 KEYMOD      EQU   $C025       ; GS-specific
+NEWVIDEO    EQU   $C029       ; GS-specific, new video register
 
 SPKR        EQU   $C030
 CLOCKCTL    EQU   $C034       ; GS-specific, Clock control register
diff --git a/auxmem.hgr.s b/auxmem.hgr.s
index e2aeeb9..abb05df 100644
--- a/auxmem.hgr.s
+++ b/auxmem.hgr.s
@@ -19,6 +19,8 @@ HGRVDU22      JSR   VDU12                  ; Clear text and HGR screen
               STA   GRON                   ; Enable Graphics
               STA   PAGE1                  ; PAGE1
               STA   CLR80VID               ; Select 40col text
+              LDA   #$80                   ; Most significant bit
+              TRB   NEWVIDEO               ; Turn off SHR
               RTS
 
 
diff --git a/auxmem.init.s b/auxmem.init.s
index 8f4e4c0..f850a84 100644
--- a/auxmem.init.s
+++ b/auxmem.init.s
@@ -218,6 +218,6 @@ BYTE00      BEQ   BYTE00A         ; OSBYTE 0,0 - generate error
             RTS                   ; %000x1xxx host type, 'A'pple
 BYTE00A     BRK
             DB    $F7
-HELLO       ASC   'Applecorn MOS 2022-12-21'
+HELLO       ASC   'Applecorn MOS 2022-12-22'
             DB    $00             ; Unify MOS messages
 
diff --git a/auxmem.shr.s b/auxmem.shr.s
index 4f59f84..0a891c8 100644
--- a/auxmem.shr.s
+++ b/auxmem.shr.s
@@ -2,7 +2,12 @@
 * (c) Bobbi 2022 GPLv3
 *
 * Routines for drawing bitmapped text and graphics in SHR mode
-* on Apple IIGS (640x200 4 colour, or 320x200 16 colour.
+* on Apple IIGS (640x200 4 colour, or 320x200 16 colour.)
 *
 
+* Enable SHR mode
+SHRVDU22      JSR   VDU12                  ; Clear text and HGR screen
+              LDA   #$80                   ; Most significant bit
+              TSB   NEWVIDEO               ; Enable SHR mode
+              RTS
 
diff --git a/auxmem.vdu.s b/auxmem.vdu.s
index 7a710e9..6659624 100644
--- a/auxmem.vdu.s
+++ b/auxmem.vdu.s
@@ -117,11 +117,11 @@ SCNTXTMAXX    DB     79, 39, 39, 79, 39, 39, 39, 39  ; Max text column
 SCNTXTMAXY    DB     23, 23, 23, 23, 23, 23, 23, 23  ; Max text row
 SCNBYTES      DB     08, 08, 08, 01, 01, 01, 01, 01  ; Bytes per character
 SCNCOLOURS    DB     03, 15, 07, 01, 01, 01, 01, 01  ; Colours-1
-SCNPIXELS     DB     08, 08, 07, 00, 00, 00, 00, 00  ; Pixels per byte
-SCNTYPE       DB     32, 32,128, 01, 00, 00, 00, 64  ; Screen type
+SCNPIXELS     DB     04, 02, 07, 00, 00, 00, 00, 00  ; Pixels per byte
+SCNTYPE       DB     65, 64,128, 01, 00, 00, 00, 32  ; Screen type
 * b7=FastDraw -> HGR mode
-* b6=Teletext -> No-op
-* b5=SHR mode on Apple IIgs
+* b6=SHR mode on Apple IIgs
+* b5=Teletext
 * b0=40COL/80COL
 
 * Colour table
@@ -361,8 +361,9 @@ PUTCHRC       PHA
               BNE   PRCHR4
               CPX   #$20
               BCS   PRCHR3                 ; Not $80-$9F
+              LDA   #$20
               BIT   VDUSCREEN
-              BVC   PRCHR3                 ; Not teletext
+              BEQ   PRCHR3                 ; Not teletext
               LDX   #$E0                   ; Convert $80-$9F to space
 PRCHR3        TXA
               EOR   #$40
@@ -593,15 +594,20 @@ VDU22         LDA   VDUQ+8
               JSR   VDU20                  ; Default colours
               JSR   VDU26                  ; Default windows
               STA   FULLGR                 ; Clear MIXED mode
-              LDA   VDUSCREEN
+              BIT   VDUSCREEN
               BPL   :NOTHGR
-              JMP   HGRVDU22               ; b7=1, graphics mode
-:NOTHGR       AND   #$01                   ; 40col/80col bit
+              JMP   HGRVDU22               ; b7=1, HGR mode
+:NOTHGR       BVC   :NOTSHR
+              JMP   SHRVDU22               ; b6=1, SHR mode
+:NOTSHR       LDA   VDUSCREEN
+              AND   #$01                   ; 40col/80col bit
               TAX
               STA   CLR80VID,X             ; Select 40col/80col
               STA   TEXTON                 ; Enable Text
               STA   PAGE2                  ; PAGE2
               STA   SETALTCHAR             ; Enable alt charset
+              LDA   #$80                   ; Most significant bit
+              TRB   NEWVIDEO               ; Turn off SHR
 * Fall through into CLS