"Hey man, what's going on tonight?"
"Be at my place by 10pm. BYOB"
"BYOB? What's that mean?"
"There's a party motherfucker, bring your own blunt. God damn"
Back in the earlier years of computers, prior to standardization, manufacturers of expansion cards put the BIOS commands for the device directly on it, stored in ROM.
Eric: Mr. Williams, I can't find a driver disk for this modem!
Mr. Williams: Duh, there isn't one! It's BYOB, the bios is ON it!