PCjr 25 years later

pcjr

[Trixter], connoisseur of old hardware, is celebrating the 25th anniversary of the PCjr. IBM's PCjr was killed only 18th months after being revealed and [Trixter] lays out exactly why. Overall, it was designed to be cheap to produce and sell, but many of the choices made it difficult to use. They used the CPU instead of DMA for floppy access; cheaper to make, but you couldn't do much during disk … [Read more...]

Adjustable breadboard power supply

psboard

This looks like a great addition to your breadboard. [Nerdz] wanted a power supply that was easily portable and adjustable. He built a custom board that plugs directly into the breadboard's power rails. It has a pot attached to the ground of a 7805 voltage regulator so the output can be adjusted from 5V to just under the supply voltage. Anything that makes a breadboard less of a rats nest is … [Read more...]

Business card AVR board updated

bcard

Evil Mad Scientist Laboratories has updated their business card AVR breakout boards to version 1.1. We suspect the changes will probably make them even more popular. The boards are designed for the ATmegaXX8 family of microcontrollers. The center has all 28 pins labeled while either end has a prototyping area. An in-system programming header is also provided. For the new version, both prototyping … [Read more...]

Stripboard Drawdio

drawdio

When we posted about the Drawdio release, mentioned how simple the circuit was and that we wouldn't be surprised if people adapted it. [Dylski] decided to build it using stripboard and parts he had laying around. He shows how he laid it out on paper so that it would fit on a 29x5 piece. It took some planning, but the end result is a perfectly functional as you can see in the video below. … [Read more...]

Design for manufacture

sparkfun

SparkFun has posted an excellent guide to the many different issues you could run into when you finally decide to get a circuit board professionally produced. We assume that most of you aren't running a professional design firm and will appreciate these tips gleaned from years of experience. They provided a rule list, Eagle DRC, and CAM file to help you get it right the first time. The end goal is … [Read more...]

Nintendo DSi teardown

dsi_teardown

[bunnie] managed to pick up a Nintendo DSi while in Japan. It seems he had the device running less than an hour before he tore it down for an impromptu hotel photoshoot. There's nothing too surprising and he mentions that the CPU certainly feels more capable than the previous model, which may explain the shorter battery life. The ARM processor sits under an RF shield directly below the WiFi card. … [Read more...]