difference between LSI-11 CPU's M7264 and M7270

Gooijen, Henk GOOI at oce.nl
Mon Sep 26 06:42:48 CDT 2005

> -----Original Message-----
> From: cctalk-bounces at classiccmp.org 
> [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Pete Turnbull
> Sent: maandag 26 september 2005 12:59
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: difference between LSI-11 CPU's M7264 and M7270
> 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,
> > here is the description. When you look at the front side, the 4 slots
> > at the left side, and the PSU is at the right side and has at the front
> > switches (DC on/off, enable/halt, and LTC on/off) and 2 LEDs (DC on and
> > 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

Thanks Pete.
I had a look at the backplane yesterday, but did not see an Hxxxx number.
There was a xx-yyyyy (?) digit number, but I will check again this evening.

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

The figure is as seen from the front side when the front cover is removed.
The "art work" shows the panel with the switches and LEDs at the right.
To remove a board from the cage you must pull the board "out of the
screen", so the magenta handles are at the front side.

The FieldGuide says that a few lines are used for something else, but
I expect (hope) that the M7270 and the M7264 usage of all connections
is identical.
It makes perfect sense that I will have to adjust the base address of
the memory on the M8044 if I install the M7264.  I will take an other
look at the memory board with the new information from you.
I will dig up the MicroNotes!
It will be interesting to see what the system does when I power it up.
The console is connected to the M7940 ... I hope to see a prompt!

Regarding the M8018 WCS option: is this "just" a chip, like FIS or the
big CIS one? I thought it was a board (module) as the M number suggests.
Anybody here has a M8018 WCS and can tell more about it?

- Henk, PA8PDP.

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