Ok i am trying to brake down the clipboard-responsible code so that i can add unicode clipboard support.. the news are not so good.
First, i saw that the code for sending text to the clipboard is
    int clipboardWriteFromAt(int count, int byteArrayIndex, int startIndex)
The thing is that we are trying to create a fully Unicode VM...this means that the characters that are sent to the VM are Unicode (> 256) and we are using a unicode TT font to render them.
Now... when i evaluate this
c:=Clipboard new.
c primitiveClipboardText:'α'    "α is unicode char 945"
the clipboardWriteFromAt is never invoked.
That's because in
    sqInt primitiveClipboardText(void)
the following expression is evaluated to TRUE
if (!(((s & 1) == 0) && (((((usqInt) (longAt(s))) >> 8) & 15) >= 8))) {
   /* begin primitiveFail */
   successFlag = 0;
   printf("primitive failed 1\n");    "This printf is mine"
   return null;
Now what in earth is THIS?
    (!(((s & 1) == 0) && (((((usqInt) (longAt(s))) >> 8) & 15) >= 8)))
Also further down it has
if (successFlag) {
   sz = stSizeOf(s);
   clipboardWriteFromAt(sz, s + BaseHeaderSize, 0);
   /* begin pop: */
   stackPointer -= 1 * BytesPerWord;
where stSizeOf goes down to assembly...
I think i am starting to abandon the fully-unicode vision and follow your instructions from the start to use code pages and preserve the internal representation of Squeak...
I don't think that i will be able to make everything unicode in a life time (does it worth it?)...