PowerBook 1400CS/166 Install Disks

You will probably have to look on places such as e-bay or Google Groups Low-end Mac. It will be a lower version (maybe 9.0.4) which you can update with updaters that are hard to find since Apple seems to have lost them from their web site. Grab these now while you can:

Alternative source of OS9 updaters - https://discussions.apple.com/thread/3460487?answerId=16786736022#16786736022

Looking at: http://www.everymac.com/systems/apple/powerbook/specs/mac_powerbook1400cs_166.ht ml it says the highest supported OS is 9.1

Are you talking about this with reference to an updater? I don't think those need to be on CD. It's been years since I needed to update OS9 but I thought you could just run the updater from the main drive.

If you have access to an OSX machine it is possible Disk Utility can work with .smi.

I was able to open a .smi from inside of Disk Utility (Tiger OS). You can then burn the file to a CD.

I can't help you with Mountain Lion. It is possible ML is so new they no longer support the opening of .smi. I can't test it myself because I run Tiger OS. If that's the case you will have to find an older computer somewhere where you can open the image.