From: blockedofcourse@foo.invalid   
      
   On 12/7/2025 10:57 AM, John Robertson wrote:   
   > Hi Folks,   
   >   
   > I've done the online searches, and know that bitsavers.org (Hi Al K. if you   
   are   
   > here) has a reasonable amount of information, however I am looking for ap   
   notes   
   > and more information than is currently archived.   
   >   
   > At the moment one chip I am researching is the MM76E (not the 40-pin EL   
   > version) ROM as I can't find the pinout anywhere - so far. I can figure it   
   out,   
   > but it is always better to have the manual if possible...   
   >   
   > Any documents found will be off to bitsavers of course, but I'm hoping that   
   > someone here has an ancient (70s!) Rockwell manual on these 42-pin spider   
   chips!   
   >   
   > Did anyone ever make an emulator for the MM78 CPU family?   
      
   I know you don't want to hear it, but it is likely a trivial job; the   
   toughest part would be "downgrading" your understanding of how   
   processors work.  Back then, they were more like "collections of   
   subcircuits" and the code patched together their interactions   
   instead of baking in particular relationships.  The manufacturer   
   likely made a simulator to encourage adoption ("Development Systems"   
   were super rare and super pricey so it was easier to run a simulation   
   of your code on a minicomputer).   
      
   But, it would likely have been made available on DECtape or possibly   
   as FORTRAN (being the "big" language of that day) sources.   
      
   Here are two documents that popped up in a search of my archive.   
   Unfortunately, my index is in disrepair as I have been migrating   
   most of the archive onto larger spindles and different machines   
   (easier to rebuild it as a batch job once it is in its new form).   
      
      
      
      
   I had been asked to evaluate a Rockwell "process controller" in the   
   mid/late 70's, hence my exposure to this.  I've not looked through   
   the documents as I suspect you can sort out if there is anything   
   of value, to you (possibly even ideas for other search criteria?)   
      
   I will look through my textbook collection to see if anything   
   else pops up.   
      
   HTH   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)