difference between LSI-11 CPU's M7264 and M7270 - test-drb@ccmp.vtda.org

26 Sep 2005

On Sep 26 2005,  8:40, Gooijen, Henk wrote:

...
  I cleaned the dust out of a small 4 slot card cage
with the power supply
...
  at the right side. I was never good at naming the BA
box types, so here is
...
  the description. When you look at the front side, the
4 slots are at the
...
  left side, and the PSU is at the right side and has at
the front 3 switches
...
  (DC on/off, enable/halt, and LTC on/off) and 2 LEDs
(DC on and run).
 The following cards are installed (I have not yet powered up this unit).

Sounds like the innards of a BA11-M, especially given the boards you
have.  Check the number on the backplane, it should be a H9270, which
is an 18-bit serpentine backplane.

...
     <------ M7270 ------> <------ M8044
------> ==================
    <------ empty ------> <------ M7940 ------> |  o o  __ __ __ |
    <------ empty ------> <------ empty ------> |       ~~ ~~ ~~ |
    <------ empty ------> <------ empty ------> ==================

 I have 2 questions from this system.
 1) As I am not that familiar with QBUS, are the cards in the correct slot?

Usually you draw the boards positions as seen from the rear (from the
handles).  Is the M7270 to the left of the M8044 when seen from that
direction?  It should be.  What you've drawn is correct for the view
...
 from the handles. 
...
  2) The M8044 says on the handle "M8044-DK"
but on the board is in the etch
...
     "M8045" and "16KW x 18 BIT"
(IIRC that last part). Strange or common ?

M8045 and M8044 are the same board but the 8045 has extra RAM for
parity and a few extra components fitted to enable it.  8044 is MSV11-D
(non-parity) and 8045 is MSV11-E (parity).   What you have is not at
all unusual.

...
  An other thing is the following.  I also have a M7264.
This board is quad
...
  sized,
 but has 4 kW memory on the CPU board. The M7270 is dual sized (with no RAM).
...
  Can I remove the M7270 and M8044 and put the M7264
instead in the above
...
  rack? 
Yes, but you may need to alter a few things, starting with the memory.
 If your M7264 has 4KW/8KB memory on it, you'll either need to change
the start address of the MSV11-D, to be at 020000(8) (= 8192 decimal),
or disable the memory on the M7264.  These processors can only address
64KB of memory, so if your MSV11 has much memory on it, you might want
to disable the 8KB on the processor.  If you do, you'll need to disable
some other things to do with refresh and BRPLY -- the M7264 produces a
refresh signal which you don't want on the bus, and responds to
refreshes and memory accesses on the bus.

The MSV11-D/E are available with 4K or 16K DRAMs, and either half- or
fully-populated, hence they can be any of 8KB, 16KB, 32KB, or 64KB,
known as MSV11-DA, -DB, DC, DD.  The second letter on the handle,
however, is different -- it tells you where the chips came from, not
the size.

...
  The reason for this swap is that I hoipe one day to
add a M8018 (WCS), and
...
  as far as I know, the WCS option does not work with
the M7270, but only with
...
  the M7264. Is this correct? 
Dunno.  As far as I know, it just plugs into one of the MICROM sockets,
where the KEV11 (EIS/FIS upgrade would go), so it may work on any
version of the 11/03.  If it's specific to one, it may be that it works
on a KD11-J (M7264-YA, without memory) but not a KD11-F (M7264, with
4KW memory) because they are different board layouts.  Or, more likely,
vice versa.

...
  And *if* the M7264 is installed, can I then move the
M7940 to the left in
...
  the
 same slot and put in the open space the M8044? 
Yes, that would be best.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York