Following the Hardware Upgrade, the Software needs to be renewed, too!
The latest PIX OS running on the 506e would be 6.3.5.125.
You can upgrade to that and use the pdm to configure the Device.
Or... you can go to ASA!
As described here ( http://www.rownet.co.uk/installing-v7-software-on-a-cisco-pix-506e/ ) you can do that quite easily.
But in short:
- Boot into Pix
- Start downloading an pdm file with copy tftp://Your_TFTP_Server_IP_Address/Your_pdmfile_name flash:pdm and disconnect the ethernet cable!
- After disconnecting, the PIX will erase the pdm from your pix, clearing the flash space for pdm
- clear flashfs
- reload your PIX into Monitor Mode / RMON
- activate your interface (interface 0 is E0, interface 1 E1)
- enter ip addr of tftp server ( server ), filename ( tftp ), ip addr of your pix ( address ) and start downloading to pix
- It will boot from tftp into ASA
- Copy ASA Image: copy tftp://Your_TFTP_Server_IP_Address/pix712.bin flash:
- Reload
Done, you got ASA.
No ASDM / PDM anymore, because not enough space, but ASA ^^