I had an AMD Duron 900 mhz running at about 53 c. This was indicated in the bios. Is this a safe or too high of temp to operated?

the max it is rated for is 85 c, so your okay for now. two things, is that temp when you've been running for a while, just booted up, idle, running a heavy application, etc. what you are doing is definitly important when mentioning temps. im guess though, since this is a bios reading, that you don't use a temp. monitor. I'd recommend motherboard monitor (5 is the latest version iirc) and set it up to monitor your cpu temps. find its idle temp (not running anything) and its max load temp (or whatever it's referred to as) which is the temp it registers when you're running a few apps or an intense game. what is your cooling situation? you have the default heatsink/fan on there? any other fans? did you remove the thermal tape and use a thermal paste instead? either way, 53 is nothing to panic about, but if you're curious you can find lots more out :)
-Krugger