Was the INSTA Cartridge a form of copy protection? Maybe a Dongle?
On boot the Cartridge simply ask you to:
PLEASE INSERT “INSTA” DISK
Here is what I got from using MDUMP: INSTA.ZIP

Pirate Challenge

This add appeared in a C64 magazine. It’s a hacker’s challenge. For $5.99 you would be sent “The Pirate Disk” that has five questions hidden deep within layers of copy protection. If you can crack your way through them all, you would get a free program.

Does anyone have more info about this? Anyone have this disk or image of it? Also do you know more about the challenge? The protection schemes? What was your reward program? Was this this program also hidden on the disk?

Ultimate Utility V6.5 is a disk loaded with copier programs and utilities. There are 25 programs on the front and back of this disk. Some notable programs are the Arts backup, Trillium crackers, Activision fixer and much more!

Doctor T’s Incredible Copiers.

This is a disk of ten copy programs and utilities. These programs are all on one side of the disk. Who is “Doctor T”?