Wasn't there something about internal drives requiring Apple firmware?
Back in the day we had to hack Apple's CD or CD/DVD driver to make non-Apple drives work and I also had to modify one kext in OSX in my Intel Mini to be able to use non-Apple external DVD drives.

Try booting off of CD by holding down cmd-opt-shift-delete

There you go.
Bear in mind that you will need a larger EEPROM for the Mac firmware. 512k vs. 1MB IIRC.
Been there, re-flashed well over 10 cards back in the day 

Sorry, I see that PowerDomain Utilies is also included in the hqx file! Thank you!   

There you go.
Bear in mind that you will need a larger EEPROM for the Mac firmware. 512b vs. 1Mb IIRC.
Been there, re-flashed well over 10 cards back in the day 

I've got a G4 Mac Mini 1.5Ghz. I have never been able to boot from the CD or indeed access a disk in it. - The only way I can eject a disk is to boot to Open Firmware and eject it there.
System Profiler always shows the disk but always without any media loaded.

At first I assumed it was because the only disks I had were 700Mb. But after sourcing some 650Mb ones they did not work either. I always get the error that the disk is not initialised.

I gave up with the optical drive at that point and eventually I got Mac OS9 installed by imaging (using iBored) the v9 install image to the internal original disk (attached) when booted from an external USB drive running OS X. Then booting from that and installing to a new IDE adaptor/mSATA disk that was temporarily connected using an USB<>IDE adaptor. Once the mSATA was installed as the internal drive this boots fine.

However, I still wanted to get the optical drive working so I replaced the original optical drive with a Panasonic UJ-875. Unfortunately as luck would have it this does not work either!

I got into thinking that it's a Master/Slave/CL thing, so messed with a tiny jumper on the IDE adaptor. But after booting in all combinations I realise that it's likely not that as the original disk had the same problem.

So before I give up ever wanting to use an optical drive in this Mac Mini is there something simple I may have done? Perhaps I've damaged the riser board that the internal and optical drive attach to?

Thanks!

Olympus Camedia Master is required to connect to old Olympus digital cameras, when you do not have any card reader compatible with the card format. The old cameras, like the C-2020Z, used serial ports to connect to the host to download pictures, which meant a proprietary application was required to talk to them. Otherwise there is certainly no reason to use this slow and buggy software.

Graphic Converter from lemkesoft has a picture browser and can be used to sort or file pictures. Since it's also a full image editing program, you can make batch conversion scripts and apply them to images you select in the browser.