Date   : Sat, 30 Oct 2010 13:24:03 +0100
From   : percy.p.person@... (Ed Spittles)
Subject: Reversing the Tube ULA (destructively)

Hi Theo
  more on microscopy:

On 30 October 2010 10:42, Ed Spittles <percy.p.person@...> wrote:
>>
>> He says that on 100x lens you get 20um x 20um photos, and on 20x you get
>> 100x100um. ?Do we know what sort of die size we're looking at? ?At 5mm x 5mm
>> and 100x that's 2500 photos.
>
> Greg James tells me that 20x is best. (He was looking at 6502) ?I've seen
an image reduced to 1500pixels across, and that would be just adequate. 3000
pixels would be comfortable, I think.

Just checked?Bal?zs?Beregnyei's?6502 die photo here
http://www.downloads.reactivemicro.com/Public/Electronics/CPU/6502%20Decaped.png
(large!)
and it's 3600 by 5700 pixels, in approx 8x8 photos. Not sure why it
came out non-square. ?It's good enough for eye-brain reversing, not
sure about image analysis.
Greg's presentation
http://visual6502.org/docs/6502_in_action_14_web.pdf
tells us he used a 10x objective and took 8x9 photos. ?Again, the
6502, so perhaps a 10micron technology?  The tiled result was 18000
pixels wide, reduced to 6000 pixels for analysis.

Cheers
Ed