David Bailey wrote: > ...it works most of the time but fails if used rapidly... > local fn DoColorizedCopyBits > < snip> > bitsPtr = bitsPtr > < snip> > end fn  If that assignment is in your actual code, then you have a bug: only 1 of the 256 pixels in your GWorld gets initialised.  Interesting issues arise if you want to make YeOldeDoColorizedCopyBittes translatable by FBtoC, one being the use of .CGrafPort ("pointer to CGrafPort"). > dim thePort as .CGrafPort CGrafPort is obsolete in Carbon. You'll have to Use CGrafPtr ("pointer to some opaque struct") instead of .CGrafPort. Robert P.