Installing newer OS on old Mac?

I found my old Performa 575 in my closet this weekend, so I dusted the thing off and plugged it in.  Everything seems to work fine, but god, it's painful to use with the outdated OS and all.  I don't know which version it's running, but it's stock, so probably real old.  The specs on this thing are pretty pathetic, but I have to know--what's the latest OS # I can safely install on this heap, and how exactly might I go about reformatting the HD and installing said OS?  I googled for a bit, but documentation on these old things isn't great, apparently; and after using PC's for years, I've become quite Mac-oblivious.

If there's nothing I can do with it, cool--I just want to get it running for the hell of it.  Help would be appreciated if anything can be done for this thing.

if it's the same as my mac LC 575, then it's too old to have a PowerPC processor, meaning it can only run up to MacOS 8.0.1, which is rather pathetic anyway.  sorry, i had to throw mine out because it was so useless.  i kept the case though, it makes a great waste paper bin.

Well then, my next question is, is 8.0.1 the stock OS that comes preinstalled on 575's?  If not, I'd very much like to upgrade to it.  See, throwing it away isn't an option for me--it's all I have for long stretches of time in an otherwise computer-deprived house.  So yeah, since it's better than nothing, it'd be cool to at least get the latest OS I can on the thing.  Instructions on how to do this/where I could find ISO plz?

Hmm, same problem here--I have one of those sitting around as well and have found that information is scarce.  Info on reformatting/installing new OS would be fucking fantastic.  Mine has some kind of wierd problem where it thinks it has like 50mb of HD space when COMPLETELY emptied out--it should have about 200.  So yeah, a reformat would be nice...

Oh yeah, one more thing: would swapping in a standard HDD be feasible, or not really?  I've never opened mine up, and I think it seems sort of unreasonable, but having a little more space is always good...

It should be real easy to find out which system version you have. Choose About this Macintosh, or whatever the command was called, from the Apple menu. Should be the first item.

As for upgrades, you can check http://www.info.apple.com/support/oldersoftwarelist.html though I wouldn't get my hopes up.

Reinstalling and reformatting is real easy, if only you have an actual OS installer. Should be impossible to fail at.

Performas can be a bit of a bitch when it comes to changing their internals, and so will finding a hd it accepts be.

Ah yes, back from the heyday of mac!
These old fuckers use SCSI drives.  And were apart of the "crappy mac" stage.
http://lowendmac.com/500/lc575.shtml
That should give you some decent info.