diff --git a/compiler/res/prog8lib/c64/syslib.p8 b/compiler/res/prog8lib/c64/syslib.p8
index 9615ec8d4..56cce7440 100644
--- a/compiler/res/prog8lib/c64/syslib.p8
+++ b/compiler/res/prog8lib/c64/syslib.p8
@@ -703,4 +703,37 @@ cx16 {
     &uword r14 = $cf1c
     &uword r15 = $cf1e
 
+    &ubyte r0L  = $cf00
+    &ubyte r1L  = $cf02
+    &ubyte r2L  = $cf04
+    &ubyte r3L  = $cf06
+    &ubyte r4L  = $cf08
+    &ubyte r5L  = $cf0a
+    &ubyte r6L  = $cf0c
+    &ubyte r7L  = $cf0e
+    &ubyte r8L  = $cf10
+    &ubyte r9L  = $cf12
+    &ubyte r10L = $cf14
+    &ubyte r11L = $cf16
+    &ubyte r12L = $cf18
+    &ubyte r13L = $cf1a
+    &ubyte r14L = $cf1c
+    &ubyte r15L = $cf1e
+
+    &ubyte r0H  = $cf01
+    &ubyte r1H  = $cf03
+    &ubyte r2H  = $cf05
+    &ubyte r3H  = $cf07
+    &ubyte r4H  = $cf09
+    &ubyte r5H  = $cf0b
+    &ubyte r6H  = $cf0d
+    &ubyte r7H  = $cf0f
+    &ubyte r8H  = $cf11
+    &ubyte r9H  = $cf13
+    &ubyte r10H = $cf15
+    &ubyte r11H = $cf17
+    &ubyte r12H = $cf19
+    &ubyte r13H = $cf1b
+    &ubyte r14H = $cf1d
+    &ubyte r15H = $cf1f
 }
diff --git a/compiler/res/prog8lib/cx16/syslib.p8 b/compiler/res/prog8lib/cx16/syslib.p8
index 06ea357f6..698e6a616 100644
--- a/compiler/res/prog8lib/cx16/syslib.p8
+++ b/compiler/res/prog8lib/cx16/syslib.p8
@@ -116,6 +116,41 @@ cx16 {
     &uword r14 = $001e
     &uword r15 = $0020
 
+    &ubyte r0L  = $0002
+    &ubyte r1L  = $0004
+    &ubyte r2L  = $0006
+    &ubyte r3L  = $0008
+    &ubyte r4L  = $000a
+    &ubyte r5L  = $000c
+    &ubyte r6L  = $000e
+    &ubyte r7L  = $0010
+    &ubyte r8L  = $0012
+    &ubyte r9L  = $0014
+    &ubyte r10L = $0016
+    &ubyte r11L = $0018
+    &ubyte r12L = $001a
+    &ubyte r13L = $001c
+    &ubyte r14L = $001e
+    &ubyte r15L = $0020
+
+    &ubyte r0H  = $0003
+    &ubyte r1H  = $0005
+    &ubyte r2H  = $0007
+    &ubyte r3H  = $0009
+    &ubyte r4H  = $000b
+    &ubyte r5H  = $000d
+    &ubyte r6H  = $000f
+    &ubyte r7H  = $0011
+    &ubyte r8H  = $0013
+    &ubyte r9H  = $0015
+    &ubyte r10H = $0017
+    &ubyte r11H = $0019
+    &ubyte r12H = $001b
+    &ubyte r13H = $001d
+    &ubyte r14H = $001f
+    &ubyte r15H = $0021
+
+
 ; VERA registers
 
     const uword VERA_BASE       = $9F20
diff --git a/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt b/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
index 140459af5..d785f75f0 100644
--- a/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
+++ b/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
@@ -339,9 +339,11 @@ internal class BeforeAsmGenerationAstChanger(val program: Program, val errors: I
     private fun getAutoIndexerVarFor(expr: ArrayIndexedExpression): MutableList<IAstModification> {
         val modifications = mutableListOf<IAstModification>()
         val statement = expr.containingStatement()
+        val dt = expr.indexer.indexExpr.inferType(program)
+        val register = if(dt.istype(DataType.UBYTE) || dt.istype(DataType.BYTE)) "r9L" else "r9"
         // replace the indexer with just the variable (simply use a cx16 virtual register r9, that we HOPE is not used for other things in the expression...)
         // assign the indexing expression to the helper variable, but only if that hasn't been done already
-        val target = AssignTarget(IdentifierReference(listOf("cx16", "r9"), expr.indexer.position), null, null, expr.indexer.position)
+        val target = AssignTarget(IdentifierReference(listOf("cx16", register), expr.indexer.position), null, null, expr.indexer.position)
         val assign = Assignment(target, expr.indexer.indexExpr, expr.indexer.position)
         modifications.add(IAstModification.InsertBefore(statement, assign, statement.definingScope()))
         modifications.add(IAstModification.ReplaceNode(expr.indexer.indexExpr, target.identifier!!.copy(), expr.indexer))
diff --git a/examples/test.p8 b/examples/test.p8
index 3c53d99ab..992a59ab3 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -1,10 +1,23 @@
+%import textio
+%zeropage basicsafe
+%import test_stack
+
 main {
     sub start() {
-        if cx16.r0 {
-                const ubyte buffer_length = 255     ; less than 256
-                ubyte[255] buffer
-                ubyte[buffer_length] buffer2
+        str anim = "1234"
+        ubyte anim_counter = 0
+
+        test_stack.test()
+
+        txt.print("loading ")
+        repeat 100 {
+            ubyte qq = anim[anim_counter/2]
+            txt.chrout(qq)
+            anim_counter = (anim_counter+1) & 7
         }
+        txt.print("done!\n")
+
+        test_stack.test()
     }
 }