[Linked Image from i46.photobucket.com]

From KLD:
Quote
The large box lower left of the framework is the power supply. The upper row of card slots starts with CO1, goes to the right. Sot six has been rewired for a 403 card (MOH). At the far end of the card slot row is the interrupter. That is what makes the clickity click sound when you are on hold. All mechanical Central Offices used to have a combination interrupter/ dial tone / ringing machine. In the KSU it is just smaller.
Thanks KLD for the pics!

I'm going to attempt to post the 2nd one here (the one without your customers mug shot)

Why do they call the 1A2 a "shoebox" KSU?
It's pretty large and I take it that the cover is removed for the pic. With the cover on it would be even larger.