diff --git a/platform/vic20.oph b/platform/vic20.oph
new file mode 100644
index 0000000..e56bd26
--- /dev/null
+++ b/platform/vic20.oph
@@ -0,0 +1,5 @@
+;;; Minimal header file for unexpanded VIC-20.
+;;; It translates to 10 SYS4109.
+.word	$1001
+.org	$1001
+.byte	$0b,$10,$0a,$00,$9e,$34,$31,$30,$39,$00,$00,$00
diff --git a/platform/vic20x.oph b/platform/vic20x.oph
new file mode 100644
index 0000000..6e50aa7
--- /dev/null
+++ b/platform/vic20x.oph
@@ -0,0 +1,5 @@
+;;; Minimal header file for expanded VIC-20.
+;;; It translates to 10 SYS4621.
+.word	$1201
+.org	$1201
+.byte	$0b,$12,$0a,$00,$9e,$34,$36,$32,$31,$00,$00,$00