Category Archives: HP

Hacking A Very Special 486

It’s fair to say that Moore’s Law is not delivering on its promise of advancing semiconductor capabilities as fast as it used to, as the limits of current fabrication techniques are being met. Where this is being written for example there are two laptops, one from the last year and one that is 11 years old, and while the new one is undeniably faster it has not overtaken the other by as much as a ten year gap between 1990s machines would have revealed.

So with older laptops being still so relatively quick, what possible attraction could there be for …read more

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Current Measurement with Oscilloscopes

What do a Rogowski coil, a magnetic core, and a hall effect sensor have in common? They are all ways you can make oscilloscope probes that measure current. If you think of a scope as a voltage measurement device, you ought to watch the recent video from Keysight Technology (see below). It is true that Keysight would love to sell you a probe, but the video is not a sales pitch, just general technical information about making current measurements with an oscilloscope.

Of course, you can always measure the voltage across a shunt resistor — either one that is naturally …read more

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Printer Scrap Becomes FPGA Devboard

These days, if you want to start learning about FPGAs, it can be a daunting experience. There’s a huge variety of different platforms and devboards and it can be difficult to know where to start. [RoGeorge] decided to take a different tack. Like a 16-year-old drag racer, he decided to run what he brung – a printer control panel cum FPGA development board (Romanian, get your Google Translate on).

[RoGeorge] was lucky enough to score a couple of seemingly defective control panels from HP Laserjets discarded by his workplace. Seeing potentially good parts going to waste, like keypads and LCDs, …read more

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Posted in HP, laserjet, printer, vhdl | Leave a comment