DIY Z80 microcomputer from scratch

„My Z80 microcomputer is hand wired using the wire-wrap prototyping technique. This method uses thin 30 gauge wire, a special wire-wrap tool, and wire-wrap sockets. The sockets have 1/2 inch long square posts, which you use the tool to wrap (or twist) the wire onto the post. As long as you have 5 or more wraps on the post for a single wire, the connection is semi-perminant. This method was used because it’s easy to change connections and is faster than soldering each wire. Wire-wrapping was a popular method used in building early computers. In fact, the AGC computer used for the NASA Apollo missions were completely wire-wrapped! After I finished my computer, I went through more than 350 feet of wire!“

http://www.derivedlogic.com/Z80%20Microcomputer/z80micro.html

DIY 40 MHz Frequency meter

This article shows how to build a small, cheap and simple frequency meter, without any fancy, out of reach components. The simple proposed design can measure frequencies up to 40 Mhz with errors below 1%! This degree of precision will be more than enough to debug most of your analog and digital circuits, and will give you the ability to analyze many aspects that you were unable to see before.“

http://www.ikalogic.com/freq_meter_2.php

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DIY wearable computer with Head Mounted Display

„Essentially he took the MyVu headset, removed one of the eye pieces, and mounted the other to his glasses to that he could see his surroundings and the UX’s screen at the same time. The MyVu is attached to the UX through the A/V output port on the UX’s port replicator dongle. With some additional addons he provided his UX with extra battery life via an external battery, and several input methods to communicate with the UX while the rest of the kit resides within the backpack.

Components include:
Main system:

  • Battery geek: BG 14-18-60External battery (60wh)
  • Sony UX380N
    • VGA/TV/LAN Dongle
  • Motorola iDen i425 (for next-to-nothing (but half dial up speed) always-on internet access)

Input/Output:

  • Modified MyVu Crystal Head Mounted Display
  • Bluetooth enabled cellphone (text and mouse input)
  • Bluetooth stereo headset (voice input and stereo output)
  • ThinkOutside Stowaway Bluetooth Keyboard
  • Logitech Bluetooth Mouse
  • Bluetooth Frogpad (text input)“

http://www.umpcportal.com/2009/07/awesome-wearable-computer-setup-is-powered-by-sony-vaio-ux-umpc

DIY Wireless keylogger

„Familiar with the concept of hardware keylogging? A hardware keylogger is a perfect solution for monitoring user activity, at very low risk of disclosure. A hardware keylogger is a purely electronic device, so no access to the operating system is required, no traces are left, and software has no possibility of detecting such a device. However, the hardware keylogger concept inherits one weakness: physical access to the keylogger is required for retrieving captured data. This problem has finally found it’s solution: a Wireless Keylogger.“

http://www.keelog.com/wireless_keylogger.html

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