I understand that Quartus II 8.0 is obsolete but I have a code base written for this device and need to make some changes to the code. The other issue is that the FPGA device is also obsolete so later copies of Quartus II no longer support it. Is it possible to get a copy of the installer, I understand that a liciense would still be required which I assume can still be obtained. Does anyone still have copies of the installer that was available on the Altera FTP site?
Intel/Altera no longer has Quartus/MaxPlusII earlier than 13.0sp1/13.1 online.
After 13.0sp1, the next earliest version available is 17.0.
Downloads of earlier versions are deprecated and not available, they were all removed from online access about March 2020.
Which FPGA device in particular are you trying to support?
If it is not supported in 13.0sp1 you are probably out of luck. You can check download device support here: