Help identify these Atari S-100 Boards (fwd)

I just discovered some *VERY* interesting S100 boards that I didn't realize I had in my box 'o S-100 boards. They seem to be some kind of Atari development/prototyping system. The boards are: 65xx Emulator, part no. 100-015-2, Rev. 2, (c) 1983 Atari [this is the PCB only] Trace Memory Interface, part no. 100-002-2 (two of these) has (3) Intersil 6402 chips and (3) 26-pin connectors (for interface to a terminal), DIP switches to select the baud rate for the 6402 chips (up to 38400 bps). Also has a 40-pin (2-rows of 20) ribbon cable connector labelled J100. One has a test sticker on it with "OK 10/25/82" written on it. 6502 Processor, part no. 100-003-2, Rev. 4 has a 6502 and some other stuff, such as a clock speed DIP switch (1, 2, 4 MHZ settings), some RAM, a 40-pin ribbon cable connector which presumably connects to the Trace Memory Interface card (labelled COMP BUS J100). I have 2 of these boards but one is incomplete (does not have all the chips the other one does, for instance the 6502). All have the Atari name and logo in yellow lettering. Any idea what this stuff is and what it was used for? If you can shed any light, please reply to dastar(a)crl.com. Thanks!