Mac starts as if in MS DOS

Hi,

For a while now my iMac (2006 model) has been starting up and shutting down in what looks like macs version of MS DOS, I think it is called open firmware, but i may be wrong. I've searched around and not really seen any solutions to this.

I was having some other issues with the mac and had a big clean out of old files and stuff. So I decided to zero(x7) it and start again from Snow Leopard and I'm now running Lion, but it still takes ages to load up and run through this DOS like system every time I start it.

Have I inadvertently turned this on somehow and can it be turn off?

Thanks in advance for your help,
Kinneas

I think somehow you've activated booting in verbose mode.

Mac OS X: How to start up in single-user or verbose mode

Restart and then reset PRAM, by immediately holding command-option-p-r (yes, all 4 at once). If you did it correctly, you'll hear the start gong again.

Run in terminal the command nvram -p .
If see a line with boot_arg v
run the command sudo boot-args=
or sudo su boot-args=
restart you computer directly after the command

If it's occurring after reinstall, it sounds like your "s" key might be stuck. If possible, try a different keyboard. If you don't, turn off/unplug your keyboard and try booting the machine.

Holding command-option-p-r on start up seems to have solved it! Thanks a lot folks, was nothing wrong with per se, it was just annoying. Thanks again

Explanation - it seems that command-y changes a setting in the PRAM/NVRAM, which should automatically revert after a complete shutdown.
If it doesn't revert, resetting PRAM does it.