heres a link to TM article and download
http://pspupdates.qj.net/Dark-AleX-r.../49/aid/113797

heres a link to a time machine configurator and descriptive article
http://pspupdates.qj.net/Time-Machin.../49/aid/115794

and this allows your plugins to work thru time machine when on a pre-5.00 cfw:
http://pspupdates.qj.net/SEPlugins-T.../49/aid/128819

these may not be the latest versions out, i would check around.
but at least it'll give you the general idea what time machine can do
hope its helpful

----Added 17/3/2009 at 9:16 PM----
ok i checked it out a little more, and to use time machine, you have to start out with 3.90 and then it can take you to 3.40 oe and i think 1.50.
i think you were best off using hellcats rf.
so is your psp bricked, or you just cant get the rf to downgrade you?