just use split, its part of the GNU utils and comes standard with all GNU/Linux distros
split -b 1400k foo foo
will split foo into a series of file <=1400 KB called fooaa, fooab, fooac etc.
split -b 700m foo foo
will create 700MB files
to joing the files just concatenate them with cat
cat foo?? > foo
or if you don't want to copy all the files to one place and then join them you can use
cat /mnt/cdrom/fooaa >> foo
swap media then run
cat /mnt/cdrom/fooab >> foo
etc.
cheers,
Alaa