Bill, I think you mean an ITT 601. There was never a 611. It had five line card slots, an intercom slot, a MOH slot and a solid-state interrupter card at the top with a white plastic chassis and light gray cover, correct?

You can add 259A or 359A panels with no problem except that they are designed for rack mounting. You really can't use them any other way since the cards plug into the front face of the mount and the back face contains the screw terminals for pin slots 1-20.

There are no limits to what you can do with 1A2; there is no software that calls the shots. It's all up to your imagination and the hardware you have to work with. Unlike electronic or digital systems, the installer determines how intelligent the system will be when it is installed.

I'm pretty sure that there was a 416 and 461 card too. Oddly, they were similar in function. I believe that the 416A allowed tie lines between two systems, where the 461 allowed for an off-premise single line set to have full functionality as a single line key set. Again, these are what I believe to be the functions, as in guesses.

Ed Vaughn, MBSWWYPBX