difference between LSI-11 CPU's M7264 and M7270

[Allison]

>
>Subject: RE: difference between LSI-11 CPU's M7264 and M7270
>   From: "Gooijen, Henk" <GOOI at oce.nl>
>   Date: Mon, 26 Sep 2005 15:37:11 +0200
>     To: "'General Discussion: On-Topic and Off-Topic Posts'"	<cctalk at classiccmp.org>
>
>> usual config is: 
>>   M7264 (quad)
>>  option2|option1
>>  option3|option4
>>  option5|option6
>> 
>> Others:
>>   M7270 |M8044
>>  option2|option1
>>  option3|option4
>>  option5|option6
>> 
>> Option1 is typically DLV11 (SLU)
>> option2 is typcailly DLV11 (SLU#2)
>> option3 is typically RXV11 (floppy)
>> option4 is typcically REV11 (floppy boot prom)
>> 
>> Allison
>
>Thanks Allison!
>Together with the info from Pete I am on the safe side to turn on power.
>BTW, I assume that you made a typo in the serpentine:
>>  option2|option1
>>  option3|option4
>>  option5|option6
>That last line should be option6|option5, or ......?
>

As shown it is correct.  2,3,5 on the left: 1,4,6 on the right.
it's one of the odder -11 backplanes.  I believe the reson for that
odd layout is when cascading multiple boxes (BA11M) the cables
orient easier as option 5 to next box topleft is the shown 
configuration and the REV-11 prom boot is nominally in option6
as bus grant continuity is not required for most memories.

My source was the Microcomputer handbook 1976/77.
I also have one with core in it.

Allison