diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/FunctionCallAsmGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/FunctionCallAsmGen.kt
index 381b1e90e..1c579c43d 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/FunctionCallAsmGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/FunctionCallAsmGen.kt
@@ -82,7 +82,7 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
             is PtAddressOf -> false
             is PtIdentifier -> false
             is PtMachineRegister -> false
-            is PtMemoryByte -> false
+            is PtMemoryByte -> return usesOtherRegistersWhileEvaluating(arg.address)
             is PtNumber -> false
             else -> true
         }
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index eaa5453f0..4342702ac 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -1,8 +1,6 @@
 TODO
 ====
 
-fix bug: txt.setchr(x, y, @(bytes+$1000))  bytes++   doesn't fill the whole screen only the first 256 bytes or something
-
 fix TODO's to assign from and to split arrays (BuiltinFuncGen + BuiltinFunctionAsmGen) -- cannot use simple single memcopy here  (6502 + IR)
 assembler, imageviewer is bigger than before  (since commit "added string.lstripped() and string.ltrimmed()" )
 
diff --git a/examples/test.p8 b/examples/test.p8
index 5e6381373..b69458724 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -6,40 +6,24 @@
 
 main {
     sub start() {
+        ubyte x
+        ubyte y
+        uword bytes = $a000
+
+        for y in 0 to 59 {
+            for x in 0 to 79 {
+                txt.setchr(x, y, @(bytes+$1000))
+                bytes++
+            }
+        }
+    }
+
+    sub stringcopy() {
         str name1 = "name1"
         str name2 = "name2"
         uword[] @split names = [name1, name2, "name3"]
         uword[] addresses = [0,0,0]
         names = [1111,2222,3333]
         addresses = names
-        ;foo("zzz")
-    }
-
-    sub foo (str sarg) {
-        ubyte[3] svar
-        txt.print_uwhex(svar, true)
-        txt.nl()
-        txt.print_uwhex(&svar, true)
-        txt.nl()
-        txt.print_uwhex(&svar[2], true)
-        txt.nl()
-        cx16.r1L = 3
-        txt.print_uwhex(&svar[cx16.r1L], true)
-        txt.nl()
-        txt.nl()
-
-        txt.print_uwhex(sarg, true)
-        txt.nl()
-        txt.print_uwhex(&sarg, true)
-        txt.nl()
-        txt.print_uwhex(sarg+2, true)
-        txt.nl()
-        cx16.r0 = &sarg[2]
-        txt.print_uwhex(cx16.r0, true)   ; TODO should be the same as the previous one  sarg+2 (13)!
-        txt.nl()
-        cx16.r1L=3
-        cx16.r0 = &sarg[cx16.r1L]
-        txt.print_uwhex(cx16.r0, true)   ; TODO should be the same as the previous one  sarg+2 (13)!
-        txt.nl()
     }
 }