No major need for it; I found the DM11-AA Tech Manual in my PDP-11 fiche set. So I doubt the brochure would answer any of the remaining questions; we'd probably need the Engineering Drawings for that. But there's so little on the DM11, it might be interesting to see the brochure. The big issue with the TM is that it has the same erroneous diagram for i) the boards in the DM11-A, and ii) their locations in the backplane, as the one in DEC-11-HDMBA-A-D, "DM11-BB modem control option manual", on pg. 1-5. The diagram there lists: M7245 Transmitter E M7244 Transmitter D M7245 Receiver M7242 Control C M7241 Control B M7240 Control A So two 'M7245's, with different functions listed! And no M7243... The DEC "Spare Module Handbook" shows: M7243 "DM11 transmitter D" M7244 "DM11 transmitter E" M7245 "DM11 receiver" so the M7245 probably _is_ the receiver; but this list shows that the 'transmitter E' card is the M7244, not the M7243 (as would be if the top line Hence my observation that it would probably take takethe ED tostraighten thins out. But as I said recently, no real need; the thing is a total canine, and I doubt very much that there are any left in the world. Noel