[Unix-jun72] svn changes?

Milo Velimirovic milov at uwlax.edu
Fri May 2 01:31:58 AEST 2008

On May 1, 2008, at 9:25 AM, Hellwig Geisse wrote:

> On Thu, 2008-05-01 at 09:04 -0400, Brad Parker wrote:
>> Via email I asked Tim about EAE support in simh, since apout has it  
>> and
>> the code claims he added it to simh, but I can't find it.
> Wasn't this called the "EIS" option? If I remember
> well, simh enabled that by default if you choose the
> CPU to be an 11/40.

No... EIS is not the same as EAE, though simh does include EIS in its  
11/40 configuration.

 From memory:

EAE is the "Extended Arithmetic Element" which provided multiply,  
divide and shift capabilities through registers in the I/O space.
See Dennis Ritchie's "Odd Comments and Strange Doings in Unix" the  
pertinent item is "A hardware story" at the the end of the document,  
cached here: < 
 > (It seems the link provided by Google to dmr's website is down...)

EIS is the Extended Instruction Set, which on the pdp11/40 (and lsi11)  
went hand in hand with FIS, the Floating Instruction Set.

See a pdp11 processor handbook for all the details.

Milo Velimirović,  Unix Computer Network Administrator
608.785.6618 Office -  608.386.2817 Cell
University of Wisconsin - La Crosse
La Crosse, Wisconsin 54601 USA   43 48 48 N 91 13 53 W

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