diff --git a/sbus-to-ztex-gateware-migen/cg3.fth b/sbus-to-ztex-gateware-migen/cg3.fth
index d2397d4..4028487 100644
--- a/sbus-to-ztex-gateware-migen/cg3.fth
+++ b/sbus-to-ztex-gateware-migen/cg3.fth
@@ -72,14 +72,28 @@ headerless
   cg3-off-dac /cg3-off-dac do-map-in to cg3-dac
 ;
 
+: dac-unmap
+  cg3-dac /cg3-off-dac do-map-out
+  -1 to cg3-dac
+;
+
 : fb-map
   cg3-off-fb /cg3-off-fb do-map-in to fb-addr
 ;
 
+: fb-unmap
+  cg3-off-fb /cg3-off-fb do-map-out
+  -1 to fb-addr
+;
+
 : map-regs
   dac-map fb-map
 ;
 
+: unmap-regs
+  dac-unmap fb-unmap
+;
+
 \
 \ Installation
 \
@@ -107,6 +121,13 @@ headerless
   then
 ;
 
+: qemu-cg3-driver-remove ( -- )
+  cg3-dac -1 <> if
+  		  unmap-regs
+		  -1 to frame-buffer-adr
+  then
+;
+
 : qemu-cg3-driver-init
 
   cg3-reg
@@ -126,6 +147,7 @@ headerless
   h# c encode-int " cursorshift" property
 
   ['] qemu-cg3-driver-install is-install
+  ['] qemu-cg3-driver-remove is-remove
 ;
 
 qemu-cg3-driver-init
diff --git a/sbus-to-ztex-gateware-migen/cg6.fth b/sbus-to-ztex-gateware-migen/cg6.fth
index 386c73c..bc1810e 100644
--- a/sbus-to-ztex-gateware-migen/cg6.fth
+++ b/sbus-to-ztex-gateware-migen/cg6.fth
@@ -73,14 +73,28 @@ headerless
   cg6-off-dac /cg6-off-dac do-map-in to cg6-dac
 ;
 
+: dac-unmap
+  cg6-dac /cg6-off-dac do-map-out
+  -1 to cg6-dac
+;
+
 : fb-map
   cg6-off-fb /cg6-off-fb do-map-in to fb-addr
 ;
 
+: fb-unmap
+  fb-addr /cg6-off-fb do-map-out
+  -1 to fb-addr
+;
+
 : map-regs
   dac-map fb-map
 ;
 
+: unmap-regs
+  dac-unmap fb-unmap
+;
+
 fload fbc_init.fth
 
 \
@@ -123,6 +137,14 @@ fload fbc_init.fth
   then
 ;
 
+: qemu-cg6-driver-remove ( -- )
+  cg6-dac -1 <> if
+  		  unmap-regs
+		  map-out-fbc
+		  -1 to frame-buffer-adr
+  then
+;
+
 : qemu-cg6-driver-init
 
   cg6-reg
@@ -144,6 +166,7 @@ fload fbc_init.fth
   /cg6-off-fb encode-int " fbmapped" property
 
   ['] qemu-cg6-driver-install is-install
+  ['] qemu-cg6-driver-remove is-remove
 ;
 
 qemu-cg6-driver-init