Date   : Fri, 12 Nov 2010 15:54:08 +0000
From   : list-a_cloud9.bbc-micro@... (Theo Markettos)
Subject: Electron Ferranti ULA reverse engineering progress

In article <4CDB3CD6.60400@...> you wrote:
> 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

According to the Spectrum ULA guy who went to visit, there isn't much
technical info there - it's all marketing etc stuff.

> 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...

Given the constraints, I wouldn't be surprised if the logic is designed at
the transistor level rather than at a gate level mapped onto transistors. 
So there might not be gate-like standard cells to extract, each gate may be
designed specifically for that application.  Though there will be some
regularity.

> [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.

It's not a terribly exciting article so not worth bothering about too much,
the relevant page is here:
http://www.cl.cam.ac.uk/~atm26/acorn/electron/ula/ferranti-r-series-cell.png
That's a different structure to the one I see under the microscope.

> 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?

Not sure there's much I can do to correct for pincushion: that's a
microscope+camera optics problem.  Probably easier to software-postprocess.

Theo