diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc25f0fc..10354e5d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,12 +2,16 @@
 
 ## Current version
 
+* `sizeof` now supports arrays.
+
 * Added `-R` option for specifying extra commandline parameters for emulators.
 
 * Added full 16-bit multiplication. 
 
 * Added preliminary support for EasyFlash.
 
+* Added preliminary support for Commander X16.
+
 * Allowed defining custom output padding byte value.
 
 * Allowed passing non-decimal numbers to the `-D` option.
diff --git a/docs/api/target-platforms.md b/docs/api/target-platforms.md
index 4469ee37..a8f2b668 100644
--- a/docs/api/target-platforms.md
+++ b/docs/api/target-platforms.md
@@ -99,4 +99,7 @@ The compiler emits COM files.
 
 * `dos_com` – a COM file for DOS on IBM PC. (very experimental)
 
+* `x16_experimental` – Commander X16; very experimental,
+as both the target configuration *and* the device itself are in their experimental phases.
+
 The primary and most tested platform is Commodore 64.
diff --git a/docs/lang/preprocessor.md b/docs/lang/preprocessor.md
index dcabc769..1c5e827b 100644
--- a/docs/lang/preprocessor.md
+++ b/docs/lang/preprocessor.md
@@ -84,7 +84,7 @@ See [the ROM vs RAM guide](../api/rom-vs-ram.md) for more information.
 
 * `WIDESCREEN` – 1 if the horizontal screen resolution, ignoring borders, is greater than 256, 0 otherwise
 
-* `CBM` – 1 if the target is an 8-bit Commodore computer, 0 otherwise
+* `CBM` – 1 if the target is an 8-bit Commodore computer (or a compatible one), 0 otherwise
 
 * `CBM_64_COMPAT` – 1 if the target is an 8-bit Commodore computer compatible with Commodore 64, 0 otherwise
 
diff --git a/examples/README.md b/examples/README.md
index 72f194f7..f2992a49 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -4,7 +4,7 @@
 
 * [Hello world](crossplatform/hello_world.mfk) (C64/C16/PET/VIC-20/PET/Atari/Apple II/BBC Micro/ZX Spectrum/PC-88/Armstrad CPC/MSX) – simple text output
 
-* [Fizzbuzz](crossplatform/fizzbuzz.mfk) (C64/C16/PET/VIC-20/PET/Atari/Apple II/BBC Micro/ZX Spectrum/PC-88/Armstrad CPC/MSX) – everyone's favourite programming task
+* [Fizzbuzz](crossplatform/fizzbuzz.mfk) (C64/C16/PET/VIC-20/PET/Atari/Apple II/BBC Micro/ZX Spectrum/PC-88/Armstrad CPC/MSX/X16) – everyone's favourite programming task
 
 * [Fizzbuzz 2](crossplatform/fizzbuzz2.mfk) (C64/C16/PET/VIC-20/PET/Atari/Apple II/BBC Micro/ZX Spectrum/PC-88/Armstrad CPC/MSX) – an alternative, more extensible implemententation of fizzbuzz
 
@@ -61,3 +61,9 @@ how to create a program made of multiple files loaded on demand
 
 * [Encoding test](msx/encoding_test.mfk) – text encoding test; displays three lines of text in three different languages,
 no more one of which will display correctly depending on the default font of your computer.
+
+# Commander X16 examples
+
+* [Palette](x16/palette.mfk) – displays the default 256-colour palette.
+
+* [Balls](x16/palette.mfk) – 16 sprites using 240 colours.
diff --git a/examples/x16/balls.mfk b/examples/x16/balls.mfk
new file mode 100644
index 00000000..09f5d23a
--- /dev/null
+++ b/examples/x16/balls.mfk
@@ -0,0 +1,92 @@
+// the emulator supports only 16 sprites:
+const byte SPRITE_COUNT = 16
+array(vera_sprite_data) sprites[SPRITE_COUNT]
+array(sbyte) vx[SPRITE_COUNT]
+array(sbyte) vy[SPRITE_COUNT]
+
+import random
+
+void main () {
+    pointer.vera_sprite_data p
+
+    byte i,j
+    word x,y
+    init_rand_seed()
+    // make balls striped
+    for i,0,parallelto,$1f {
+        for j,1,parallelto,$f {
+            sprite_bitmap[nonet(j<<5) + i] *= j
+        }
+    }
+    for i,0,paralleluntil,SPRITE_COUNT {
+        p = sprites[i].pointer
+        // bitmap is at $10000:
+        p->address = $800
+        p->x.lo = rand()
+        p->x.hi = rand() & 1
+        p->y = rand()
+        // no collision, above all layers, no flipping
+        p->ctrl0 = $c
+        // 32×32 pixels, different palette offsets
+        p->ctrl1 = $a0 | (i & $f)
+        vx[i] = 1 - (rand() & 2)
+        vy[i] = 1 - (rand() & 2)
+    }
+    vera_upload_large($10000, sprite_bitmap.addr, sizeof(sprite_bitmap))
+    vera_upload_large($40800, sprites.addr, sizeof(sprites))
+    // enable sprites:
+    vera_poke($40020, 1)
+    while true {
+        for i,0,paralleluntil,SPRITE_COUNT {
+            p = sprites[i].pointer
+            x = p->x
+            y = p->y
+            x += vx[i]
+            y += vy[i]
+            p->x = x
+            p->y = y
+            if x == 0 { vx[i] = 1 }
+            if x >= 640-32 { vx[i] = 0-1 }
+            if y == 0 { vy[i] = 1 }
+            if y >= 480-32 { vy[i] = 0-1 }
+        }
+        vera_upload_large($40800, sprites.addr, sizeof(sprites))
+    }
+}
+
+
+array sprite_bitmap = [
+$00,$00,$00,$00,$00,$00,$11,$11,$11,$11,$00,$00,$00,$00,$00,$00,
+$00,$00,$00,$00,$01,$11,$11,$11,$11,$11,$11,$10,$00,$00,$00,$00,
+$00,$00,$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,$00,$00,
+$00,$00,$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,$00,$00,
+$00,$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,$00,
+$00,$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,$00,
+$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,
+$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,
+$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,
+$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,
+$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,
+$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,
+$00,$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,$00,
+$00,$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,$00,
+$00,$00,$00,$11,$11,$11,$11,$11,$11,$11,$11,$11,$11,$00,$00,$00,
+$00,$00,$00,$01,$11,$11,$11,$11,$11,$11,$11,$11,$10,$00,$00,$00,
+$00,$00,$00,$00,$01,$11,$11,$11,$11,$11,$11,$10,$00,$00,$00,$00,
+$00,$00,$00,$00,$00,$00,$11,$11,$11,$11,$00,$00,$00,$00,$00,$00
+]
+
diff --git a/examples/x16/palette.mfk b/examples/x16/palette.mfk
new file mode 100644
index 00000000..0c39ae2d
--- /dev/null
+++ b/examples/x16/palette.mfk
@@ -0,0 +1,24 @@
+void main() {
+    word i
+    byte hn, ln
+    // 256-colour text mode for layer 0
+    vera_poke($40000, $21)
+    // 8×8 tiles, 64×64 tile map
+    vera_poke($40001, $35)
+    // 2× zoom in
+    vera_poke($40041, $40)
+    vera_poke($40042, $40)
+    i = 0
+    while i < $2000 {
+        vera_poke(i, $A0)
+        if i.lo & $7f < 64 {
+            ln = lo(i>>1) & $1f
+            hn = lo(i>>2) & $e0
+            vera_poke(i+1, hn | ln)
+        } else {
+            vera_poke(i+1, 0)
+        }
+        i += 2
+    }
+    while true {}
+}
diff --git a/include/x16_experimental.ini b/include/x16_experimental.ini
new file mode 100644
index 00000000..2938502d
--- /dev/null
+++ b/include/x16_experimental.ini
@@ -0,0 +1,40 @@
+; Commander X16
+; VERY EXPERIMENTAL
+; The device's haven't been completed yet, so this platform configuration may not run on the final device
+; Use only for goofing around plz
+
+[compilation]
+arch=cmos
+encoding=petscii
+screen_encoding=petscr
+modules=loader_0801,c64_kernal,x16_hardware,c64_panic,stdlib
+
+[allocation]
+; list of free zp pointer locations is the same as C64
+zp_pointers=$FB,$FD,$43,$45,$47,$4B,$F7,$F9,$9E,$9B,$3D
+segments=default,himem0
+default_code_segment=default
+segment_default_start=$80D
+segment_default_codeend=$9eff
+segment_default_datastart=after_code
+segment_default_end=$9eff
+
+segment_himem0_start=$c000
+segment_himem0_codeend=$dfff
+segment_himem0_datastart=after_code
+segment_himem0_end=$dfff
+
+[define]
+CBM=1
+WIDESCREEN=1
+KEYBOARD=1
+JOYSTICKS=0
+HAS_BITMAP_MODE=1
+
+[output]
+style=single
+format=startaddr,allocated
+extension=prg
+labels=vice
+
+
diff --git a/include/x16_hardware.mfk b/include/x16_hardware.mfk
new file mode 100644
index 00000000..e1ae8d88
--- /dev/null
+++ b/include/x16_hardware.mfk
@@ -0,0 +1,103 @@
+// TODO: bankswitching
+
+
+volatile byte vera_addr_hi @ $9f20
+volatile byte vera_addr_mi @ $9f21
+volatile byte vera_addr_lo @ $9f22
+volatile byte vera_data1 @ $9f23
+volatile byte vera_data2 @ $9f24
+volatile byte vera_ctrl @ $9f25
+volatile byte vera_ien @ $9f26
+volatile byte vera_isr @ $9f27
+
+struct vera_layer_setup {
+    byte ctrl0
+    byte ctrl1
+    word map_base
+    word tile_base
+    word hscroll
+    word vscroll
+}
+
+asm void set_vera_layer_internal(pointer.vera_layer_setup ax, byte y) {
+    sta __reg
+    stx __reg+1
+    stz vera_ctrl
+    lda $14
+    sta vera_addr_hi
+    stz vera_addr_mi
+    sty vera_addr_lo
+    ldy #0
+    __set_layer_internal_loop:
+    lda (__reg),y
+    sta vera_data1
+    iny
+    cpy #sizeof(vera_layer_setup)
+    bne __set_layer_internal_loop
+    ? rts
+}
+
+asm void set_vera_layer0(pointer.vera_layer_setup ax) {
+    ? ldy #0
+    ? jmp set_vera_layer_internal
+}
+
+asm void set_vera_layer1(pointer.vera_layer_setup ax) {
+    ? ldy #0
+    ? jmp set_vera_layer_internal
+}
+
+inline void vera_poke(int24 address, byte value) {
+    vera_addr_lo = address.b0
+    vera_addr_mi = address.b1
+    vera_addr_hi = address.b2
+    vera_ctrl = 0
+    vera_data1 = value
+}
+
+inline void vera_fill(int24 address, byte value, word size) {
+    word i
+    vera_addr_lo = address.b0
+    vera_addr_mi = address.b1
+    vera_addr_hi = address.b2 | $10
+    vera_ctrl = 0
+    for i,0,paralleluntil,size {
+        vera_data1 = value
+    }
+}
+
+void vera_upload_large(int24 address, pointer source, word size) {
+    word i
+    vera_ctrl = 0
+    vera_addr_lo = address.b0
+    vera_addr_mi = address.b1
+    vera_addr_hi = address.b2 | $10
+    for i,0,paralleluntil,size {
+        vera_data1 = source[i]
+    }
+}
+
+inline void vera_upload(int24 address, pointer source, byte size) {
+    byte i
+    vera_ctrl = 0
+    vera_addr_lo = address.b0
+    vera_addr_mi = address.b1
+    vera_addr_hi = address.b2 | $10
+    asm {
+        ? ldy #0
+        __vera_upload_loop:
+        ? lda (__reg),y
+        ? sta vera_data1
+        ? iny
+        ? cpy size
+        ? bne __vera_upload_loop
+    }
+}
+
+struct vera_sprite_data {
+    word address
+    word x
+    word y
+    byte ctrl0
+    byte ctrl1
+}
diff --git a/src/main/scala/millfork/env/Environment.scala b/src/main/scala/millfork/env/Environment.scala
index 90a13ffd..da4ff232 100644
--- a/src/main/scala/millfork/env/Environment.scala
+++ b/src/main/scala/millfork/env/Environment.scala
@@ -599,8 +599,8 @@ class Environment(val parent: Option[Environment], val prefix: String, val cpuFa
           case Some(thing) => thing match {
             case t: Type => t.size
             case v: Variable => v.typ.size
-            case a: InitializedArray => a.elementType.size * a.contents.length
-            case a: UninitializedArray => a.sizeInBytes
+            case a: MfArray => a.sizeInBytes
+            case ConstantThing(_,  MemoryAddressConstant(a: MfArray), _) => a.sizeInBytes
             case x =>
               log.error("Invalid parameter for expr: " + name)
               1