I'd guess that 'Mac clamshell blue' would be a blue iBook.
But that still doesn't give enough information. Check the system's specs; what we need to know is the CPU speed, total amount of RAM it has, and the HD size.
If the Mac is an iBook (as it most likely is), the newest possible version is
this. But it could also be
this or
this.
From those you can check what is the latest
possible OS to install on that model, 10.3 or 10.4. Anything
newer than those listed for each model will not install and will not work, as the Mac
does not meet the system requirements for later OS.
Once you know what is the exact Mac model, and therefore the latest possible OS it tolerates, there are a few more things to look at;
- RAM. How much RAM do you have? 256 MB is the absolute minimum for any Mac OS X since 10.2 to boot to - the more the better. Again, confirm against the specs on the links to make sure you have as much RAM as is possible for that model.
- Mac OS X install discs. Since that Mac did not in any case ship with Mac OS X installed, you can't use the discs that shipped with the Mac to install it (those which came with your Mac don't have it, and the discs that shipped with a Mac are always CPU specific: you can't use the install discs that came with e.g. a later model of iBook or a G4 or an Intel based anything to install to that iBook).
You will need the standard
retail version of Mac OS X install discs. For Mac OS X 10.3 and 10.4 those discs are black in color and contain the word
retail on them. For Mac OS X 10.2 the disc was, if I remember correct, white with a jaguar patterned "X" but still the disc containing the word
retail. If the install discs are gray, they will not work, period. Neither will they work if there is
upgrade printed on them (can't use upgrade install for going from OS 9 to Mac OS X 10.anything).
The install discs need also to be on
CDs, not DVDs, as the optical drive shipped with that computer does not read DVDs yet - bear in mind your computer was shipped at least ten years ago.
If your Mac is that newest one listed, with firmware, and you have a newer PPC-based Mac and firmware cable, it could be possible to use target mode to get the system installed there.
I just noticed the word 'tiger', so for your Mac we will need it to be the newest possible of that kind (the only one supporting 10.4), with enough RAM etc etc, and with
black Mac OS X 10.4 retail disc set supplied on
CDs.
- Firmware, in some cases. If all of the above are as they should, we can look at that the next. But until all the other details are confirmed, it will not do miracles.
I'd personally probably keep the Mac with OS 9, or consider some PPC version of Linux for it - to keep it with an OS that runs smooth and fast on it. Even the newest of those blue clamshells is at least 10 times slower than the new Macs, so especially if you have or use a newer one, you will definitely notice the difference.