diff --git a/projects/examples/blank.tal b/projects/examples/blank.tal
index 24d1808..82f35a6 100644
--- a/projects/examples/blank.tal
+++ b/projects/examples/blank.tal
@@ -21,7 +21,7 @@
 |60 @Audio3     [ &vector $2 &position $2 &output $1 &pad   $3 &adsr   $2 &length $2 &addr $2 &volume $1 &pitch $1 ]
 |80 @Controller [ &vector $2 &button   $1 &key    $1 ]
 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel  $1 ]
-|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save   $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save   $2 &stat $2 &delete $1 &append $1 ]
 |b0 @DateTime   [ &year   $2 &month    $1 &day    $1 &hour  $1 &minute $1 &second $1 &dotw $1 &doty   $2 &isdst $1 ]
 
 ( variables )
diff --git a/projects/examples/demos/asma-piano.tal b/projects/examples/demos/asma-piano.tal
index a6ae192..d239a3f 100644
--- a/projects/examples/demos/asma-piano.tal
+++ b/projects/examples/demos/asma-piano.tal
@@ -2,7 +2,7 @@
 
 |00 @System     [ &vector $2 &wst      $1 &rst    $1 &pad   $4 &r $2 &g $2 &b $2   &debug $1 &halt $1 ]
 |10 @Console    [ &vector $2 &read     $1 &pad    $5 &write $1 &error  $1 ]
-|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( vectors )
 
diff --git a/projects/examples/demos/drum-rack.tal b/projects/examples/demos/drum-rack.tal
index 8c7c2d0..b371f8b 100644
--- a/projects/examples/demos/drum-rack.tal
+++ b/projects/examples/demos/drum-rack.tal
@@ -30,7 +30,7 @@
 |70 @Midi       [ &vector $2 &channel  $1 &note   $1 &velocity $1 ]
 |80 @Controller [ &vector $2 &button   $1 &key    $1 ]
 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel $1 ]
-|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/examples/demos/font.tal b/projects/examples/demos/font.tal
index cfb1cf2..ec3579b 100644
--- a/projects/examples/demos/font.tal
+++ b/projects/examples/demos/font.tal
@@ -12,7 +12,7 @@
 
 |00 @System  &vector $2 &pad     $6 &r      $2 &g     $2 &b      $2
 |20 @Screen  &vector $2 &width   $2 &height $2 &pad   $2 &x      $2 &y      $2 &addr $2 &pixel $1 &sprite $1
-|a0 @File    &vector $2 &name    $2 &length $2 &success $2 &load $2 &save   $2 &stat $2 &delete $1
+|a0 @File    &vector $2 &name    $2 &length $2 &success $2 &load $2 &save   $2 &stat $2 &delete $1 &append $1
 
 ( variables )
 
diff --git a/projects/examples/demos/piano.tal b/projects/examples/demos/piano.tal
index 2baac75..2948b9e 100644
--- a/projects/examples/demos/piano.tal
+++ b/projects/examples/demos/piano.tal
@@ -27,7 +27,7 @@
 |70 @Midi       [ &vector $2 &channel  $1 &note   $1 &velocity $1 ]
 |80 @Controller [ &vector $2 &button   $1 &key    $1 ]
 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel  $1 ]
-|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/examples/devices/file.load.tal b/projects/examples/devices/file.load.tal
index 97372e5..429d16f 100644
--- a/projects/examples/devices/file.load.tal
+++ b/projects/examples/devices/file.load.tal
@@ -4,7 +4,7 @@
 
 |00 @System [ &vector $2 &pad $6 &r $2 &g $2 &b $2 ]
 |20 @Screen [ &vector $2 &width $2 &height $2 &pad $2 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1 ]
-|a0 @File   [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File   [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/examples/devices/file.save.tal b/projects/examples/devices/file.save.tal
index 0d24c50..f3ff575 100644
--- a/projects/examples/devices/file.save.tal
+++ b/projects/examples/devices/file.save.tal
@@ -3,7 +3,7 @@
 ( devices )
 
 |00 @System     [ &vector $2 &pad    $6 &r      $2 &g     $2 &b      $2 ]
-|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/examples/devices/file.tal b/projects/examples/devices/file.tal
index 8f32eba..083de14 100644
--- a/projects/examples/devices/file.tal
+++ b/projects/examples/devices/file.tal
@@ -8,7 +8,7 @@
 |00 @System     [ &vector $2 &pad    $6 &r      $2 &g     $2 &b      $2 ]
 |10 @Console    [ &pad    $8 &write  $1 ]
 |20 @Screen     [ &vector $2 &width  $2 &height $2 &pad   $2 &x      $2 &y $2 &addr $2 &pixel $1 &sprite $1 ]
-|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/examples/gui/picture.tal b/projects/examples/gui/picture.tal
index c7ea9c1..c50f072 100644
--- a/projects/examples/gui/picture.tal
+++ b/projects/examples/gui/picture.tal
@@ -7,7 +7,7 @@
 
 |00 @System [ &vector $2 &pad $6 &r $2 &g $2 &b $2 ]
 |20 @Screen [ &vector $2 &width $2 &height $2 &auto $1 &pad $1 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1 ]
-|a0 @File [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/library/asma.tal b/projects/library/asma.tal
index b41b0c6..50aed77 100644
--- a/projects/library/asma.tal
+++ b/projects/library/asma.tal
@@ -24,6 +24,9 @@
 )
 
 @asma-assemble-file ( src-filename* dest-filename* -- )
+	#01 .File/append DEO
+	DUP2 .File/name DEO2
+	#01 .File/delete DEO
 	;asma/dest-filename STA2 ;asma/src-filename STA2
 
 	;asma-init-first-pass JSR2
diff --git a/projects/software/asma.tal b/projects/software/asma.tal
index d6b2805..0fcaaeb 100644
--- a/projects/software/asma.tal
+++ b/projects/software/asma.tal
@@ -2,7 +2,7 @@
 
 |00 @System     [ &vector $2 &wst  $1 &rst    $1 &pad   $4 &r $2 &g $2 &b $2   &debug $1 &halt $1 ]
 |10 @Console    [ &vector $2 &read $1 &pad    $5 &write $1 &error  $1 ]
-|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( vectors )
 
diff --git a/projects/software/calc.tal b/projects/software/calc.tal
index d080849..ee40950 100644
--- a/projects/software/calc.tal
+++ b/projects/software/calc.tal
@@ -35,7 +35,7 @@
 |30 @Audio0     [ &vector $2 &position $2 &output $1 &pad   $3 &adsr   $2 &length $2 &addr $2 &volume $1 &pitch $1 ]
 |80 @Controller [ &vector $2 &button   $1 &key    $1 ]
 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel  $1 ]
-|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 ]
+|a0 @File       [ &vector $2 &name     $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1 ]
 
 ( variables )
 
diff --git a/projects/software/launcher.tal b/projects/software/launcher.tal
index b374d76..150a632 100644
--- a/projects/software/launcher.tal
+++ b/projects/software/launcher.tal
@@ -22,7 +22,7 @@
 |20 @Screen  &vector $2 &width   $2 &height $2 &auto $1 &pad $1 &x      $2 &y      $2 &addr $2 &pixel $1 &sprite $1
 |80 @Controller [ &vector $2 &button $1 &key    $1 ]
 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel  $1 ]
-|a0 @File    &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1
+|a0 @File    &vector $2 &name $2 &length $2 &success $2 &load $2 &save $2 &stat $2 &delete $1 &append $1
 |b0 @DateTime   [ &year   $2 &month    $1 &day    $1 &hour  $1 &minute $1 &second $1 &dotw $1 &doty $2 &isdst $1 ]
 
 ( variables )
diff --git a/src/devices/file.c b/src/devices/file.c
index 1409cbc..1f8a4d4 100644
--- a/src/devices/file.c
+++ b/src/devices/file.c
@@ -107,11 +107,11 @@ file_read(void *dest, Uint16 len)
 }
 
 Uint16
-file_write(void *src, Uint16 len)
+file_write(void *src, Uint16 len, Uint8 flags)
 {
 	if(state != FILE_WRITE) {
 		reset();
-		if((f = fopen(current_filename, "ab")) != NULL)
+		if((f = fopen(current_filename, (flags & 0x01) ? "ab" : "wb")) != NULL)
 			state = FILE_WRITE;
 	}
 	if(state == FILE_WRITE)
diff --git a/src/devices/file.h b/src/devices/file.h
index 7fd3dfa..ce45c1c 100644
--- a/src/devices/file.h
+++ b/src/devices/file.h
@@ -12,6 +12,6 @@ WITH REGARD TO THIS SOFTWARE.
 
 void file_prepare(void *filename);
 Uint16 file_read(void *dest, Uint16 len);
-Uint16 file_write(void *src, Uint16 len);
+Uint16 file_write(void *src, Uint16 len, Uint8 flags);
 Uint16 file_stat(void *dest, Uint16 len);
 Uint16 file_delete();
diff --git a/src/uxncli.c b/src/uxncli.c
index 5407e85..48f45bd 100644
--- a/src/uxncli.c
+++ b/src/uxncli.c
@@ -87,7 +87,7 @@ file_deo(Device *d, Uint8 port)
 		poke16(d->dat, 0x6, file_read(&d->mem[peek16(d->dat, 0x8)], peek16(d->dat, 0x4)));
 		break;
 	case 0xb:
-		poke16(d->dat, 0x6, file_write(&d->mem[peek16(d->dat, 0xa)], peek16(d->dat, 0x4)));
+		poke16(d->dat, 0x6, file_write(&d->mem[peek16(d->dat, 0xa)], peek16(d->dat, 0x4), d->dat[0xf]));
 		break;
 	case 0xd:
 		poke16(d->dat, 0x6, file_stat(&d->mem[peek16(d->dat, 0xc)], peek16(d->dat, 0x4)));
diff --git a/src/uxnemu.c b/src/uxnemu.c
index 28e2fff..498a497 100644
--- a/src/uxnemu.c
+++ b/src/uxnemu.c
@@ -379,7 +379,7 @@ file_deo(Device *d, Uint8 port)
 		poke16(d->dat, 0x6, file_read(&d->mem[peek16(d->dat, 0x8)], peek16(d->dat, 0x4)));
 		break;
 	case 0xb:
-		poke16(d->dat, 0x6, file_write(&d->mem[peek16(d->dat, 0xa)], peek16(d->dat, 0x4)));
+		poke16(d->dat, 0x6, file_write(&d->mem[peek16(d->dat, 0xa)], peek16(d->dat, 0x4), d->dat[0xf]));
 		break;
 	case 0xd:
 		poke16(d->dat, 0x6, file_stat(&d->mem[peek16(d->dat, 0xc)], peek16(d->dat, 0x4)));