if you are reasonably good with a soldering iron you could build an EEPROM reader and just extract the EEPROM, then soft mod it...
I did a 1.6 last month. You only need a PC if you're going to make an action replay, or to burn the chimp ISO to disc or FTP its contents to your xbox.
Thank you for your comments, I was trying to avoid ruining a controller so I was thinking of an adapter for the usb drive. I know there are some limitations, but if I format the usb drive in order to be, let's say instead of 16GB I'll format it for it to be 2 or 4GB, will this work?
the video tutorial also has a follow up on how to read the EEPROM from the xbox.
Why do you say a an older desktop? I don't see where it would help.
xboxhdm doesn't always play nice with adaptors