OT: Perl problem

[Tony Butler <lists@xxxxxxx>]

I know there's gonna be some perl whizzes here, so perhaps you could help
me
out as someone not at all familiar with perl:

I need to read in a text file about 15Mb in size and basically split it
into 80
chars per line + a new line char on the end.
and spit it out again

eg. instead of AGATCAGTACTGACTTGATCAGTTACGTCATGTACGT
have
AGATATC
CATGACT
TAGCATA
CATGATA
[obviously that wasn't 80 chars, per line, but u get the idea.

I'm thinking coz it's such a large file that reading it ann in one go isn't
a
good idea :/  Am complete n00b to perl, so would appreciate any help.

cheers,

Tony