At 09:24 AM 12/9/2015, Mike Boyle wrote: I don't need photos - I worked with carts from the time I entered radio (1969) until the last of my clients abandoned them several years ago. I have installed, maintained and repaired hundreds of cart machines in the course of my career. If anyone is interested I can scan and post the 1976 edition of the NAB standard to tape cartridge systems. Dale H. Cook, Radio Contract Engineer, Roanoke/Lynchburg, VA http://plymouthcolony.net/starcityeng/index.html