What i know about the TA-082 downgrader is that it lets you downgrade psp's that have a TA-082 motherboard
which could not be downgraded to 1.5
until now
PSP HISTORY
first PSP 2.50->2.60->2.71->1.5->3.02 OE-A->3.02 OE-B->3.03 OE-A->3.03 OE-B->3.03 OE-C