Warning: this is a long post. Today I racked my TU56 and TC11. I connected the TC11 to the TU56 with the two interface cables. I hooked up an AC power cord to the TU56. After turning on my H720 power supply and checking the voltages, I hooked up the +5, -15, and ground wires from the H720 power supply to the spade connectors on the TU56 and the TC11. I then opened up my 11/40, removed my M9312 bootstrap terminator from the last unibus slot (on my RK11-D), moved the M9312 to the unibus-out slot on the TC11, and ran a unibus cable from the slot on the RK11D (where the M9312 previously was located) to the unibus in slot on the TC11. I then powered everything up (11/40, RL02, RK05, TU56, VT100). This configuration has two RL02 drives, an RK05, and the newly added TU56. I have the appropriate bootstrap ROMs in the M9312. IIRC, the RK05 ROM also contains the dectape bootstrap code. I put a "never-used" DecTape on both drives, wrapped it around the take up reel 4 or 5 times, set the TU56 in local mode and pressed the forward switch to wind the tape a little more. I then loaded the address of the M9312 and pressed the start button. The @ prompt appeared on the console. This showed that the unibus signals and the M9312 are working in the TC11. I then decided to boot RT11 from the RK05 drive. It booted fine. The system seemed to be working normally and adding the TU56/TC11 did not adversely affect anything. Then I decided to test out the DecTape drive to see if it would respond to RT11 commands. Although there was nothing on the Dectapes, I did a DIR DT0:. The drive 0 reel began spinning and spun back to the beginning and the tape came off the take up reel and kept spinning. I flipped the unit 0 toggle switch from the REMOTE position to the OFF position, then wrapped the dectape back on the reel a few turns, set the switch to LOCAL, and wound it using unit 0's forward/reverse switch. I did the same thing with unit 1 (DIR DT1:). Exact same results. The tape winds and goes off the reel. If I attempt to do an INIT DK0: or INIT DK1:, the tapes run in forward motion until they are totally wound on the take up reels and then keep spinning. When it runs off the reel and I turn the DT0 or DT1 unit's REMOTE/LOCAL switch to the OFF position, RT11 returns an error message to the VT100 console. If I attempt to boot off a Dectape (entering DT, DT0, or DT1 at the M9312 @ prompt), the drives spin in forward direction until they wind the tape all the way onto the take up reel and then keep spinning. The indicator lights on the right side of the TC11 panel seem to be working fine, and when the tapes wind off the reel and I flip the REMOTE/LOCAL switch to OFF, the error light with come on. So it seems that the TC11 and TU56 are communicating with the 11/40 system, and the system can send commands to either dectape unit 0 or unit 1, and the TU56/TC11 will respond. My question now is: If I want to initialize a blank, never-used Dectape so I can use it under RT11, am I doing the right thing by typing INIT DT0: or INIT DT1: ? How is the dectape unit supposed to respond when I issue an INIT DT0: command? I would assume that it should not wind the tape until it winds it all the way off the reel. Where do I go from here? It seems that I'm mighty close to LIFT-OFF!!! I'll post some pics of the racked TU56/TC11 on my web site soon. Ashley http://www.woffordwitch.com