Power Management Console

We are creating a lab of 16 servers here at NetAdminTools.com to test various configurations in a simulated enterprise environment. One of the first problems we needed to solve was remote power management. If you are running a data center, you should seriously consider a commercial product like the APC MasterSwitch. We don’t have that […]

Serial Port Multiplexer

As we mentioned in the Remote Power Console article, we have a lab of 16 servers that we are using to test various configurations we will use in articles for NetAdminTools.com. We needed a way to access the consoles of the servers via a serial port, but we didn’t want to plunk down $500 or […]

Build Your Own Cat5 Cable Tester – Introduction

We designed and built a device that will test the basic integrity of a straight through or crossover cable. All you have to do is plug the cable into the two ends of the box. The X LED will light if the cable tests OK for a crossover cable. The S LED will light if […]

Build Your Own Cat5 Cable Tester – Part 1

Part 1 – How to wire Cat5 cables, and how they work. There are many different schemes for wiring Category 5 cables, EIA/TIA 568A and 568B are the most common. We wrote up a couple pdf diagrams for these you can refer to: 568A, 568B . 568B is quite widely used, especially in the US; […]

Build Your Own Cat5 Cable Tester – Part 2

Part 2 – Circuit Design Now that we know how a Cat5 cable works, we can design a circuit to test the cable. We do know that for straight-through cables we need to ensure 1-1, 2-2, 3-3, and 6-6. For crossover cables we need to ensure 1-3, 2-6, 3-1, and 6-2. We also need to […]

Build Your Own Cat5 Cable Tester – Part 3

Part 3 – Creating the circuit board [ Note: There is an update on this process on Coprolite here that includes pictures and instructions for using a new press that is available. ] The first step to creating the circuit board is laying it out electronically. We use PCB, a program that runs on *NIX […]

Build Your Own Cat5 Cable Tester – Part 4

Part 4 – drilling the PC board and assembling Drilling the board is kind of tricky. I bought a really cheap drill press called an Octopus from Jameco. Here is a picture with a board ready to drill with the drill press: The drill bit size is key to a successful project. I use #69 […]

Z8 Encore Development Kit

One interesting thing is that over the last few years, the worlds of microcontrollers and network administration have started to overlap. Here at NetAdminTools we have used microcontrollers of various types for various applications from pwer control to console servers in our homebrew section. Many microcontrollers have the ability to run IP stacks and network […]

Coprolite Z-80 Homebrew Computer Documentation Finished

Agatha has been working since, oh, around 1979 to build the perfect Z-80 homebrew computer. Many adventures in the mean time. Some pieces were completed in ’89, the main circuit was breadboarded in ’91, most of the circuit was soldered up in ’93, but it wasn’t until today, July 7th 2003, that Agatha finally finished […]