Date   : Thu, 11 Nov 2010 07:09:57 +0000
From   : philpem@... (Philip Pemberton)
Subject: Electron Ferranti ULA reverse engineering progress

On 10/11/10 18:45, Theo Markettos wrote:
 > This article:
 > http://www.docstoc.com/docs/22805065/PROGRAMMABLE-LOGIC-DEVICES-(PLD)
 > (page 86, .doc page 26)
 > gives the layout of a Ferranti C-series cell.  The layout on the above
 > doesn't correspond directly to my photo, but it looks topologically 
similar.
 > I haven't traced through all the parasitic bipolar transistors to see if
 > there's any difference.  On the photo it looks like dark green is 
N-dopant,
 > purple is P-dopant and light green is metal.

Don't the Manchester Museum of Science and Industry (MOSI) have an 
archive of materials from Ferranti?
Ah, here we go: http://www.mosi.org.uk/media/33870530/ferrantiltd.pdf

Might be worth having a word with them to see if they have any relevant 
information kicking about in the archives... are there any listmembers 
near Manchester who could go down and have a look around?
Timespan would probably be 1984 to 1990, which narrows it a bit.

 > So the bad news is this isn't a sea of gates, it's a sea of transistors.
 > That means it's not simply a case of drawing up a netlist and 
throwing it at
 > a synthesis tool - logical functions need to be drawn up from the sea of
 > resistors and transistors.  Quite possibly reverse engineering tools 
won't
 > cope so well with that.

If you can get a transistor netlist, you could -- in theory -- write a 
program to do successive abstraction and circuit identification. 
Probably be quicker to do it manually, though...

[R-series]
 > Their cell structure is given in:
 > 
http://www.sciencedirect.com/science/article/B6V0X-47WTWY2-2C/2/a553fd812b073c97d40e804cb9759fa1
 > That's different in that it provides a quad-emitter current source 
and two
 > extra double-emitter transistors.

"Not available under your institution's access plan."
$22 for a copy through Elsevier.. I think I'll just get an inter-library 
copy through the University library for a quid unless someone wants to 
slip a photocopy "under the table" as it were.

 > This article is by Peter Robinson who designed the video ULA:
 > http://portal.acm.org/citation.cfm?id=800740
 > and mentions C-series ULAs - but it's 1983.

There's some other good stuff on the ACM Digital Library -- mostly by 
Frank Ramsay of the Ferranti Hollinwood Microelectronics Centre. A 
search for "Ramsay uncommitted logic array" will find them.

 > Now I need to write some code to control the XY stage so I can take 
aligned
 > pictures...

And maybe correct for that pincushion distortion too, so the images can 
be stitched seamlessly... maybe lensfun could be used for that?

-- 
Phil.
philpem@...          
http://www.philpem.me.uk/