Date   : Fri, 12 Nov 2010 19:03:32 +0000
From   : philpem@... (Philip Pemberton)
Subject: Electron Ferranti ULA reverse engineering progress

On 12/11/10 15:54, Theo Markettos wrote:
> According to the Spectrum ULA guy who went to visit, there isn't much
> technical info there - it's all marketing etc stuff.

Ah, shame.
(and I'm still waiting for my copy of the ULA book, bah.)

> 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.

Another idea successfully scotched :(

> 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.

Perhaps the layout was tweaked slightly over time to improve the circuit 
design?

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

Hence why I suggested lensfun -- it's an open-source library to do lens 
distortion correction.

If you could get a slide with a pre-printed grid onto the microscope, 
that would be the ideal reference to use for calibrating things.

I suppose the next logical step is to get hold of a decapped Tube ULA... 
or get a full set of X/Y-stepped images of the Electron ULA and reverse 
engineer that first, then move onto the Tube ULA.

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