Car Alarms: 86 cadillac, passlock, cads

Question
Not sure I understand this, I've never had a car with a security system. You mean the ignition lock must be replaced with one that accepts a GM-cut key for this security system, or that my friend can get GM to cut a key that fits this ignition AND is correct for the security system?
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hope I have the facts right here, this is second hand. A friend with a 86 Cadillac replaced the ignition lock, and now the car won't start apparently due to alarm system. Whats involved in correcting this?
-----Answer-----
Correct. depending on which Cady, the passlock 1 or 2
system is in play. You need to get the GM keys cut
and programmed to it or no start possible.

Sorry, but that's what you seem to be experiencing.

Gonna have to get GM involved.

ALARMTEK

Answer
Whoever is now the registered owner has to go to
GM, tell them the make model and vin of the car, verify
ownership, then they will cut a coded chip key for the
ignition. It's called PASSLOCK. It's an ignition
imobilizer. There is also a horn blarring, headlight
flashing system in most Cads too. But your trouble
is Passlock.

Contact the local dealer for rates and availabilty.