Texas Instruments EPROM Chip

A few years back I bought a cheap mono-microscope from Lidl for about 50 bucks. The maximum magnification isn't that great (256x) and the lens quality leaves a lot to be desired, but it is a solid piece of cast iron furniture, and came with a few goodies like a mountable digital camera. That only runs at a paltry 320x280 res though to I took this pictures with my phone. I've uploaded the original resolution photos too, which you can access by clicking the images in the post.



I've had two of these Texas Instruments EPROM chips for years too. I bent the pins down in one of them to let it lie lower on the microscopes stage. As far as I know, these were manufactured in the 1980's and are 16 Kbit's in size. I couldn't find details on these exact model of chips, so apologies for any errors.



In the first image, you can see the clear window in the top, which allows a view into the magic memory circuitry inside. To reprogram the chip, these circuits had to be first exposed to UV light to destroy the previous state of each gate. I used to think that's where the term "flash" came from when referring to reprogramming a chip, but it appears to be unrelated.



As I increase the magnification, you can make out the Texas Instruments logo nestled neatly in one corner of the transistors. It really is tiny, but quite large compared to what they can achieve nowadays.



This was as far as I could go with the magnification because of the restrictions caused by the height of the chip. It's about 160x as far as I can remember.



The megabytes!! Well, not really...



I thought it best to include some kind of size reference for those who are curious.



The surface of the chip was quite interesting too! This is the little metal semi-circle you can see on the edge of the chip. These fine details were practically unnoticable to the naked eye.



Some form of chemical reaction to human sweat no doubt.



I included this shot because it reminds me a bit like the moon. It's a 40x view of the edge of the chips window.

I hope someone found this interesting (I deliberately put off posting these images until nitro2k01 got back from his holidays :) ). I also have a 5.2mp CMOS sensor from a dismantled Toshiba camcorder which I might give the same treatment sometime in the future.