Monthly Archives: December 2007

Write only memory from Signetics

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Reading Bob Pease’s website can be both enlightening as well as entertaining as he recounts the ‘creation’ of the Signetics 9046xN Random Access Write Only Memory. To make a long story short, an engineer in the 1970s got fed up with filling out massive amounts of paperwork when writing datasheets that was not being looked over so he created the write only memory mentioned above. The datasheet can (found here and here) got approved and added into products catalogs from Signetics which were distributed to customers. The management teams realized that the chip was fake (and probably read the datasheet for the first time) when customers started inquiring about pricing and availability. In the end, Signetics decided to take a humorous approach and pay to have the datasheet published as a two-page April fools joke in Electronics Magazine. It seems that many companies have begun to focus on streamlining internal paperwork which would hopefully lead to less disgruntled engineers, however, companies these days seem to have less tolerance for humor. With the ease of on-line publishing, every single company that has any visibility is subjected to some level of ridicule and often makes matters worse by sending cease and desist notices. This makes knowing the difference between parody and libel that much more important than ever.

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IC Friday: Sony’s (Toshiba’s) Emotion Engine

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This week, we have the Playstation 2 Emotion Engine. Upon doing some background research, I came across this nice article regarding the design of the PS2 memory subsystem by Rambus.  On a side note, I had to subject this chip to an acid bath twice so as not to risk cracking it when I removing the die from the package. The was that some of the surface scratches actually ended up removing part of the metal layer on to and exposing some of the chips innards. Next time I run into a chip that is mostly metal on top, I may try to exploit this technique to remove some of the cover. I might also try to use a UV laser that my department just bought.

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Free Books: WikiBooks

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As per my previous post, I have started working out the waveforms to interface a Sony dualshock 2 controller. I decided to go with a Cypress PSoC instead of a standard 8051 because it has a built in SPI controller thereby making the bit-banging much easier. The downside is that I don’t have a C compiler built into the development suite, but that is all right, I am pretty good with assembly. In the process of setting this board up and testing a few things, I found the embedded systems section of wikibooks quite useful. The whole electrical engineering section looks pretty good. The pages can be edited by anonymous readers just as easily as wikipedia, however, I have not found anything terribly wrong in the limited time I spent looking at the site. Over all, it seems like a decent place to learn for beginners and to contribute for experts.

Adding a Playstation 2 controller to a Sony PSP Slim (part 0)

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Ever since I learned to make truckloads of money on the internet, I have been mulling over the idea of buying myself a slim PSP. The main motivation for the purchase would be a few fun games that are PSP exclusives. The problem is that I don’t have any use for the portable aspect of the system and would actually prefer to keep it plugged into the TV. The slim PSP has component output capability, however, you still have to hold the device to play it. While looking at Hack A Day, I saw several ( 1 ) ( 2 ) methods to augment the inputs on the PSP, all involving directly wiring buttons and potentiometers directly to the PSP mainboard. A better option would be to attach a Playstation 1/2 controller port to the PSP so that a wireless PS2 controller can be used. Luckily, Jameco has some tutorials on communicating with the controller. I guess its a good time to get back to work with that 8051 board I built some time ago and see if I can get the interface to work.

( Broken PSP image is from mylife. )