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In antedeluvian times, I used a solution called "Magna-See" to make magnetic tracks on recording tape visible.
It was a suspension of magnetic particles in Carbon Tetrachloride (now a banned carcinogen.)
A more environmentally favorable version is now marketed as "Sprague-Mag."
I propose a
similar electrostatically attracted substance which could be painted on Flash Memory (USB sticks, Memory cards) to see patterns of digital bits under an appropriate microscope.
Mostly useful for those who like to take stuff apart to see how it works, and happen to have electron microscopes available.
Magna-See
http://en.wikipedia.org/wiki/Magnasee
Substance to make mag tape tracks visible [csea, Feb 16 2009]
Sprague-Mag
http://www.sprague-...library/sprgmag.pdf
Iron particles in Dichloro Fluoroethane [csea, Feb 16 2009]
Jump Drive Capacity Meter
http://www.lexar.co..._secureII_plus.html
As jutta mentioned, not very pretty (and this is the manufacturer's site, not the retailer's) [Canuck, Feb 17 2009]
Aspex Corp - Purveyors of electron microscopes
http://www.aspexcor...m/products/sem.html
For all your microvisualisation needs (apparently). No prices listed, I notice, so unlikely to be cheap! [DrBob, Feb 17 2009]
Wireless World, January 1975
http://www.qrzcq.co...s-World-1975-01.pdf
Technology mentioned in my anno. See magazine page 10/PDF page 48, "News of the Month", under the heading "Liquid crystals for electron observation". [notexactly, Apr 23 2019]
Images of the above-mentioned flash drive with a capacity meter on it, because the above-linked page is gone and not archived in the Wayback Machine
https://www.google....re+ii+plus&tbm=isch
Lexar JumpDrive Secure II Plus. Surprisingly modern-looking and capacious (up to 8 GB) for 2001 (if the date on one of the reviews I read is true, which it probably isn't because the other two reviews had dates of 2008 and 2011) [notexactly, Apr 23 2019]
[link]
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I thought this was about some kind of full/empty indicator on a flash drive. |
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Flash memory is solid state, not magnetic. I don't think you'd sense the electrons. I could be wrong. |
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An electron microscope would probably interfere with the operation of flash memory. |
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Does anyone remember the images of operating magnetic bubble memory (popular in the late 1970s)?
How were they captured? |
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My thoughts were the same as [po]. That would be a good idea. |
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You wanna look at machine code? Eeew! Machine
code is nasty and boring. It looks like machine
code, which is nasty and boring. |
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//You wanna look at machine code//
Only in object files. |
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Not possible with an ordinary microscope. The visible light with the shortest wavelength is violet at about 400nm. The chips you will be observing however, will be made with a process below 100nm. |
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To actually see anything you will need either an electron microscope or some sort of ultraviolet microscope. This kind of stuff is expensive and beyond the price range of ordinary folks. |
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Po, paix120 - USB thumb drives with a storage remaining bar on the outside exist; I saw some of those yesterday at a large California electronics retailer. (They weren't very pretty otherwise, unfortunately.) |
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//Not possible with an ordinary microscope//
Perhaps that's why [csea] mentions an electron microscope. |
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Why not just read sectors on the usb drive with a hex editor ?? |
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I had in mind the aesthetic, rather than the forensic. I wouldn't bother looking at machine code; image, waveform, or other data files would likely be more interesting. |
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I just thought it would be interesting to see if the charge which makes flash memory function could be made visible. Cost or practicality aren't the goals, this is the HB, after all! |
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//Carbon Tetrachloride (now a banned carcinogen.) // Haven't heard of that since ye olde dry cleaning days... |
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The other day I learned this was baked a few decades ago. I saw a mention of it in an old electronics magazine I read (hoping to find info on some old power resistors I found). I can't find it again the same way on this computer, so I'll have to check the history on the computer I found it on. Back in a bit… |
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(later) See [link]. Here's what it says, in case you don't want to or it doesn't work: |
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// Liquid crystals for electron observation
A simple technique has been developed for the observation of electron pulses flowing through an integrated circuit. The technique employs liquid crystals. Conventional i.c. test equipment determines whether an i.c. is functioning properly but is of little value in determining exactly why and where it has failed. With the new technique, developed by RCA, it is possible to observe where the electron flow has been interrupted at a defect. This is made possible by the normally clear liquid crystal which reflects or refracts light when stimulated by an electric current. A drop of nematic liquid crystal is placed on the surface of the i.c. so that all the rod-like molecules align in the same direction. The i.c. is placed in a conventional microscope and illuminated by light passed through a set of polarizers arranged so that none of the light reaches the microscope's eyepiece under normal conditions. However, when the i.c. is operating, the refractive index changes caused by the electrons' electric fields allow light to pass through the polarizers and, in effect, give the viewer a "live" picture of the pulses or signals flowing in the i.c. The circuits can be examined at various speeds and at normal operating voltages—eight to ten volts for m.o.s. circuits and as low as two or three volts for bipolars. // |
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(The OCR was surprisingly good. I only had to correct about 5 small errors, 3 of which were just hyphenations so not the OCR's fault. But I had to delete a line break after just about every word, which was annoying.) |
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This reminds me of that thing I promised to invent for [beanangel] a couple of years ago, just on a smaller scale. I would link to that but I can't find it again. |
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