[Bioperl-l] Conversion of Phred 33 -> Phred 64 quality

[Mark A. Jensen]

Hi folks,
I know I could RTFM, but maybe someone knows off the top of their head: 
I understand that Illumina at one time made a switch in the constant 
added to quality scores to generate the FASTQ that comes off their 
instruments. This leads to a certain incomparability of data before and 
after that switch. This is about all I know of the issue; does anyone 
here have experience with this? Are there any BP modules that do this 
translation?
much appreciated-
MAJ