MathJax Test

April 12, 2017

Apparently the mathjax CDN is closing at the end of April.

Our blog has a MathJax plugin that uses this CDN, so we will be affected (if anyone uses it).

This is a test to see if I can use it!

Simple shortcode version \(E=mc^2\)
Native format $$E=mc^2$$
Not getting far \(x^2\).
Ah ha, need to select not default from the plugin configuration.

f(x)=x^2 = 4
\rightarrow x=2

Update: Well it’s May now, and the above sort of still works. Not sure the last multiline thing ever did.


December 3, 2015

Really just so I remember what works for me. There are plenty of pages Google will find you, and mostly their suggestions work ie

CTRL-SHIFT-u <followed by hex code of the char you want and RETURN>

For most X applications, eg pidgin, browsers, etc that works, but not emacs or the command line.

For emacs CTRL-X 8 RETURN <then hex code> RETURN


Embedded video test

September 11, 2015

Just seeing this this work. I just cut and paste the <video> markup from into the “text” editor (rather than “Visual”) of WordPress.

I had to adjust the width to get it to fit in my odd, fixed width theme.

Alternatively from the visual editor I can do “Add Media” and select “Insert from URL” and then paste in the URL to the video, in this case, and then I get the following:

Protected: Access Test Two

July 28, 2014

This content is password protected. To view it please enter your password below:

Plugin reminder

July 8, 2013

This is really just a reminder that we’ve added a couple of plugins to blog.inf. Comment control and anti-spam. And that we need to do a proper blog post on the systems pages to tell people about them.


This is a test post from my iFriend account

February 19, 2013

iFriends can’t create new blogs, but they can be given permission to existing blogs.

Comments renabled, with anti-spam plugin also enabled.

PCB Reference Designation

March 9, 2011

While trying to fix my daughter’s Nintendo DS (which wasn’t a complete success, I managed to replace the slot1, it powers up and plays games, but now won’t charge 🙁 ). I wanted to know what component “F1” may be. While Googling I came across a cached web page from which was down, but seems back now. So this useful info doesn’t get lost, I’m reposting the cached info here.

Reference Designation – Reference Designations are letter and number codes assigned to items that are part of an assembly. This ‘shorthand’ code allows components in a printed circuit board to be found easily while working on a board assembly or locating them and their complete descriptions in a Bill of Material or parts list.

Standard Reference Designations for Electrical Equipment can be found published in ANSI Y32.2 1975/IEEE STD 315. Below is a partial list of the reference designations used in electronics.

A Assembly

AR Amplifier

AT Attenuator; Isolator

B Blower, Motor

BR Bridge Rectifier

BT Battery

C Capacitor

CB Circuit Breaker

CP Coupler

CR Crystal Rectifier (Diode)

D Diode; Thyristor; Varacter

DC Directional Coupler

DP Diplexer

DL Delay Line

DS Display; LED Lamp

E Terminal

F Fuse

FB Ferrite Bead

FD Fiducial

FL Filter

G Generator, Oscillator

HW Hardware

HY Circulator

J Jack Connector (Least Movable)

JP Programming Jumper

K Relay
L Coil; Inductor
LS Loud Speaker/Buzzer

M Measuring equipment, Meter

MH Mounting Hole

MK Microphone

P Plug Type Connector (Most Moveable)

PS Power Supply

Q Transistor

R Resistor, or Potentiometer

RN Resistor Network

RT Thermistor

S Switch

T Transformer

TB Terminal Block

TC Thermocouple

TP Test Point

U Integrated Circuit or inseparable assembly

V Electron Tube, Photoelectric Cell

VR Voltage Regulator

W Cable Transmission or Wire Jumper or Busbar

X Socket

Y Crystal, Oscillator