7 Aug
2011
7 Aug
'11
11:48 a.m.
I think you said the system worked before installing the TM11. The
grants and everything should still be fine. If you only extended the
Unibus with the TM11, you shouldn't need to change anything or add
grant cards. There were 4 or 5 11/05 backplanes. I thinK the Unibus
troubleshooting guide shows some of them. I assume your memory is in
the cpu backplane, and that you only have the the cpu backplane and
the RK11-D backplane.
Does the RK05 still work?
If in doubt about the BC11A going to the TM11, you can swap it out
with the one going to the RK05 and see what happens.
Paul
On Sat, Aug 6, 2011 at 11:25 AM, B M <iamvirtual at gmail.com> wrote:
With the help of various knowledgeable people on this
list, it was
pointed out that
I did not have the connection to the tape drive controller in the
correct position.
To test the tape drive, I used the programmer's console on my PDP-11/05 to
issue a read command to a mounted tape. ?When I issued a read command by
depositing a command into the TMA-11 command register, the tape advanced
slightly and then stopped. The 'Bus Grant Late' error was set in the TMA-11
status register. ?The status register did indicate the controller and tape drive
were both ready. No data was read in.
The read command was issued while the processor is halted.
This particular system did not originally have any external devices hooked up
to it.
Beginning at the processor, the system has the following components installed:
? ? KD11-B ? ? ?PDP-11/05
? ? LS11 ? ? ? ? ?line printer card (connects to a Centronics 101A printer)
? ? MM11-U ? ? 16K x 16 core memory
? ? MM11-U ? ? 16K x 16 core memory
? ? RK11-D ? ? ? RK05 disk controller
(See http://www.iamvirtual.ca/collection/systems/minis/PDP11-10/Boards.html
for details)
The BC11 cable leading to the TMA-11 controller is put on the Unibus
out connection
at the last slot of the RK11-D controller.
Based on previous posts from others, I suspect I don't have the processor grant
set up correctly.
I am currently reading several different manuals to get a description of how the
grant lines should be hooked up. ?I have read many descriptions of the
signalling,
but I have not located information on where to use the Grant Continuity cards
or making changes to the wire-wrapped bus. ?In my case, I will need to make
changes to the bus, since I do not have any of the Grant Continuity cards ;-)
Am I on the right track to assume that the problem ?is likely to be
the processor
grant wiring, or should I be looking elsewhere?
Many thanks for any pointers!
--barrym