All Firmware availablity thanks to http://pspcustomfirmware.com/
Official Firmware:
Spoiler warning:
- 1.x Series Downloads
- PSP OFW 1.50
- PSP OFW 1.51
- PSP OFW 1.52
2.x Series Downloads- PSP OFW 2.00b
- PSP OFW 2.01
- PSP OFW 2.50
- PSP OFW 2.60
- PSP OFW 2.70
- PSP OFW 2.71
- PSP OFW 2.80
- PSP OFW 2.81
- PSP OFW 2.82
3.x Series Downloads- PSP OFW 3.00
- PSP OFW 3.01
- PSP OFW 3.03
- PSP OFW 3.10
- PSP OFW 3.11
- PSP OFW 3.30
- PSP OFW 3.40
- PSP OFW 3.50
- PSP OFW 3.51
- PSP OFW 3.52
- PSP OFW 3.70
- PSP OFW 3.71
- PSP OFW 3.72
- PSP OFW 3.73
- PSP OFW 3.80
- PSP OFW 3.90
- PSP OFW 3.93
- PSP OFW 3.95
4.x Series Downloads- PSP OFW 4.00
- PSP OFW 4.01
- PSP OFW 4.05
5.x Series Downloads- PSP OFW 5.00
- PSP OFW 5.01
- PSP OFW 5.02
- PSP OFW 5.03
- PSP OFW 5.50
- PSP OFW 5.51
6.x Series Downloads- PSP OFW 6.00
- PSP OFW 6.10
- PSP OFW 6.20 = PSP and PSPGo (Japan Update Only)
- PSP OFW 6.20 = US Only
- PSPGo OFW 6.20 = US Only
- PSP OFW 6.30
- PSP OFW 6.31
- PSP OFW 6.35
- PSP OFW 6.37
- PSP Go OFW 6.37
- PSP OFW 6.38
- PSP Go OFW 6.38