RK11-D "diskless" test ZRKJE0???

[Robert Armstrong]

   I have an 11/04 with an RK11-D.  I have a couple of RK05s, but I 
wanted to test the controller before I start working on the drives.  The 
PDP11 Diagnostic Handbook says that ZRKJ?? "checks only the 
drive-independent logic of the RK11 controller. no drive is needed..."  
I assumed that meant it was a diskless test, but now I'm not sure that's 
true.  Can anyone confirm or deny this? Does anyone have a listing of 
ZRKJE0?

   My RK11-D has the BC11 drive cable plugged into the backplane, but 
the free end of the cable is just lying on the floor.  No drive is 
connected.  The test fails with

     RK11 LOGIC TEST I
     MAINDEC-11-DZRKJ-E

     REGISTER NOT CLEARED
       PC   REGADD    RECVD
     002560  177402  100000

  177402 is the RKER register and bit 15 is DRE - "Drive Error". 
According to the manual this bit is set when the AC power to the drive 
is lost, which given that I don't have a drive at all, doesn't sound 
unreasonable.  Continuing ZRKJ?? also gives

     REGISTER NOT CLEARED
       PC   REGADD    RECVD
     002560  177404  140200

     RKCS ERROR
       PC    WROTE   READ
     002636  000002  140202

177404 is the RKCS register and the first two bits are ERROR and HARD 
ERROR.  These are both set by the DRE bit in RKER and aren't really a 
surprise.

   I'm starting to wonder if this diagnostic really works w/o a drive 
attached, or if these errors are expected.

Thanks,

Bob