On Jan 19, 12:43, lothar felten wrote:

> i don´t know if this is a hardware (bus?)
> error, or maybe the tape is bad.
> the tapes i use are unused original dec TK50
> tapes, i made several ones, because i thought
> it might be a tape error, but
> all tapes are the same.
>
> hardware:
> PDP-11/83, 4megs of ram, TK50, two RD54
> (maxtor), two RL02 disks.
> qbus cards (top to bottom):
> *cpu (quad)
> *memory (quad)
> *controller for RL02 disks (quad)
> *controller for RD54 disks (double)
> *controller for TK50 (double)
> *network controller (double)

FWIW, I don't know about the tape error, but that layout looks OK apart
from the fact that if it's an 11/83, the memory shold be in the first slot
and the CPU in the second.  The essential difference between an 11/73 and
an 11/83 is that the 11/83 uses PMI memory.  Assuming your backplane is the
right one, in a BA23 or BA123 box, and that your memory is a single 4MB
board, you should swap them round, otherwise what you actually have is an
11/73.

I assume your RD54 controller is a genuine DEC RQDX3, so it's in the right
place.  It's possible you have an old version of the firmware on it, but it
should still work even if you do.

> i didn´t find a kind of terminator, but i
> didn´t change the order of the
> cards since i picked the box up.
> there are no empty slots between the cards,
> and i´m not sure if the Qbus
> need a special terminator.

There normally isn't an extra terminator in an 11/73 or 11/83, unless you
add an expansion backplane.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York