Monthly Archives: March 2008

Serial over CAT5 working

Posted on by
Reply

I spent a few hours this evening perfecting my soldering skills. I’ve created two ‘Y’ cables that split Cat5 cable into both ethernet and serial comms. I have one end plugged into my server and the other end is currently in my office. Between the two locations is the normal Cat5 wiring with no modifications. The serial connection is removed before the cable hits the switch and nobody notices.

Once I’ve tidied it all up I’ll do a writeup. I’m also trying to connect my Mac Classic to the rest of my house using a serial cable. Cleverly I’ve made a Mini-DIN 8 to DB9 cable and wired it backwards. It spews junk to my terminal and that’s about it. I’ll be fixing that tomorrow then.

Goodbye one hour

Posted on by
Reply

Clocks go forwards tonight so we all lose an hour. Whee, I now get to resync back to School Wakeup Time and BST at the same time. There’s going to be lots of groggy zombieness on Monday morning.

Went into Scunthorpe to do some shopping, and it pissed it down all over us. I bought an umbrella and it went inside-out within half an hour of using it.

Video Editing With iMovie

Posted on by
Reply

Spending the weekend at Amy’s. As usual I have my Macbook with me, and once again it’s being really rather useful. This time it isn’t remotely connecting me to a VPN, or anything special like that; this time it’s doing some video editing with iMovie.

Amy’s digital camera records video, but only in 1 minute segments. She’s recorded some video from a live music session in a local pub and wanted a way to stitch them back together to put onto YouTube. My first reaction was to use Windows Movie Maker since it comes free with XP and is fairly easy to use. However, after half an hour of faff we came to the conclusion it didn’t like her computer or camera’s video.

First we had to find the software which, unusually, wasn’t available by default on the machine. Then once it was installed, it happily complained that .mov files aren’t valid Windows Movie Maker files. Yeah nice one Microsoft!

iMovie, on the other hand allowed us to glue the videos together, add cheesy titles and render back to a video suitable for sending to YouTube.

My Mac seems to be developing a fault, or is just being strange. If I show a fairly complex image on the screen and twist the lid hinge (as though adjusting the screen so I can see it better) the display corrupts. It’s not major screen corruption, but the odd random pixel will display the ‘wrong’ colour. It’s as if the screen draws all pixels of one colour the inverse of what they should be. I have a feeling it’s a heat issue.

Serial Comms over Cat5

Posted on by
Reply

I came across a really interesting hack to power, control and run a wireless access point, all from one piece of Cat5 cable. It relies on the way 100 meg ethernet only uses two pairs in the cable, leaving two other pairs unused (a fact exploited by some network admins who need to run more machines than they have cable runs for by using a splitter).

I don’t have a wireless access point on my roof that needs power, serial and data comms. However it got me thinking. Currently my serial terminal is sat on a table next to my server, which is a bit pointless. It’d be much more useful downstairs. I don’t want to run a long serial cable around my house though, the place has enough wire creatively hidden as it is.

So what I plan on doing is creating two ‘splitter’ boxes; one end will have a standard RJ45 socket for a long piece of ethernet cable, the other end will have a short ethernet cable with plug, and a short serial cable with plug. Two of these devices, one on each end of a regular ethernet cable, will allow me to squirt serial and ethernet down a single cable run.

I’ll have to use software flow control though, and probably lower the baud rate to overcome any interference, but it should be good enough for a text terminal. If it works, I may build another pair to send serial comms into my office to hook my A1500 up to my server for file transfers.

Focus Stealing is Bad

Posted on by
Reply

From Wikipedia:

Focus stealing is when a program not in focus (e.g minimised or the in background) places a window in the foreground and redirects all keyboard input to that window. This is considered a major annoyance by most users because the program may steal the focus while their attention is not on the computer screen, such as when typing while reading copy to the side. This will cause everything typed after the window appeared to be lost.

(From their entry on Focus Stealing)

Not only might it cause you to lose work, accidentally delete data or send things to the printer, but it really disrupts your workflow. A few minutes ago I was working on a PowerPoint presentation, and had Outlook open in the background. Without warning it just forced its way to the front to ask me the terribly important question of whether I want to AutoArchive my emails.

Would have been much better if it’d flashed the task bar at me instead. With the exception of a critical event such as a battery about to run out, a hard disk in danger of catastrophic failure, or something else where there is an immediate danger of data loss/hardware damage should the user be interrupted.

It’s not just Windows that does this. Yesterday I managed to disable my UPS on my Linux server, but kept the USP software running. Being a critical event, the UPS software started sending alerts to every logged in console in the hope I would see it. I did because it smeared all over my IRC client’s display.

This is a valid time when focus stealing is appropriate. Unfortunately it then became highly irritating since the error message kept appearing even when I was attempting to fix the problem. It’s not easy reading documentation or editing config files when

Broadcast message from (root):

Device ‘BelkinUPS’ is not responding, blah blah blah fix it now blah blah

Is being scrawled all over your screen every 30 seconds.