blog.world3.net

Same old Tory party, what happened to the LibDems?

21/06/2010 – 13:43

Selling off rail track built with £5bn of public money for a mere £1.5bn. Remove waiting time limits from the NHS, thus driving people to go private.

Same old, same old. This coalition is a joke.

By mojo | Posted in politics | Comments (0)

Mouse+Joystick “computer” mode for the Retro Adapter

18/06/2010 – 18:18

I have just finished updating mouse support on the Retro Adapter so that it now supports a mouse and joystick simultaneously. I am still trying to think of a good name for it but for the moment I am calling it “Computer Mode” because it is ideal for emulating machines like the Amiga or Atari ST which use both a mouse and joystick. No need to unplug or re-configure anything, it just works.

Hopefully the next batch of RAs will arrive soon and I can get on with selling them.

By mojo | Posted in Retro Adapter, electronics, hardware, microcontrollers | Comments (0)

Dating Recordings by Power Line Fluctuations

18/06/2010 – 18:14

An interesting article.

Summary: Using power fluctuations in the national grid police claim to be able to date a recording precisely. The fluctuations affect any mains connected equipment, and allegedly even battery powered devices.

The police seem to love this kind of highly dubious forensic evidence. Let’s look at their record.

Fingerprints – not unique and never a perfect match like on TV, in fact matching is very much an art. Unreliable.

DNA – started out as a 1 in 1,000,000,000 chance of a sample matching two people, now it turns out that even with a good sample it’s more like 1 in 1,000,000 (i.e. 60 other people in the UK match).

DNA amplification – taking a small sample of DNA and build it up. The Omagh bombing trial collapsed after it was revealed to be bunk.

Firearms residue – a single spec was enough to convict Barry George until it was revealed that it was worthless as evidence. An innocent man spends years in jail.

CCTV – video evidence is powerful and solves crimes, except that most of the time it doesn’t.

Lie detectors – need I even go into them?

By mojo | Posted in law | Comments (0)

Making the Umax PowerLook 2100XL scanner work on Windows 7

15/06/2010 – 14:56

I had an interesting challenge at work a few weeks ago. A customer wanted a new PC running Windows 7 but he needed to keep using his rather old A3 scanner, a Umax PowerLook 2100XL. Umax only provide Windows XP drivers and installing them on Windows 7 stops the system starting up.

Something about the combined installer for the software and drivers was preventing it from working.

The solution was to install the software on a Windows XP machine and then copy the files manually from the XP system to the Windows 7 one. I then pointed Windows 7 to the copied files when it requested drivers for the scanner. The application program was copied in the same way and I simply set up a shortcut on the start menu pointing to the program file.

Aside from the main program directory the drivers were spread out in various system directories. It took a while to find them all.

It took me a long time to sort all that out. There are a lot of posts on the internet written by people with the same or similar scanners who are unable to make them work on Vista or Windows 7. As far as I know we are the only people who have ever managed to make it work with Windows 7.

By mojo | Posted in hardware, software, windows | Comments (10)

Maplin Soldering Fume Extractor mini review

12/06/2010 – 23:38

I decided it was time to stop breathing in leaded solder fumes and get a fume extractor. Being on a limited budget getting a new iron with one built in or a larger unit was out of the question. Actually we have an iron with extractor on it at work (Blackjack hot-air rework station with very handy electric de-soldering tool) and it works brilliantly. Maybe one day.

Maplin were for once actually the cheapest source of desk-top extractors so I decided to take a chance on their £15 model. Turns out it was quite a good choice as it seems to work pretty well. It produces about 55dB at 30cm which is about where it needs to be on the desk to work well. The noise is just about acceptable, not quite enough to be annoying or distracting and it fades into the background pretty quickly. It’s about the same as a noisy PC fan.

It takes up a fair bit of room compared to an iron-mounted or vice-mounted version but you can angle it up and down which helps when using PCB holders and the like. It seems to such most of the fumes away from your face. Some still get through but I find I don’t the the usual symptoms like headaches, watering eyes, dry throat etc.

It comes with three filters. No idea how long they will last, obviously it depends entirely on how much you use the fan. They are easy to remove and clean, and fairly cheap to replace.

By mojo | Posted in electronics | Comments (0)

… and so it begins

08/06/2010 – 22:52

Massive public service cuts and farming jobs out to private companies. Tell me again Mr Cameron, Mr Osborne, how is this different to the 1980s?

Actaully, to be fair, it is different. It’s worse.

Cuts are inevitable, but doing so much so soon will cause a double dip recession. Getting rid of government jobs and replacing them with private ones costs more, puts people out of work and on to benefits, and you end up with poorer services.

There is a responsible way to do this and then there is the Tory way. As usual they look out for the rich, make money for private companies with lucrative government contracts and screw everyone else.

Dave was right, this is going to hurt.

By mojo | Posted in politics | Comments (0)

Making a one session temp folder in Windows

30/05/2010 – 17:16

Back in the Amiga days we had a RAM disk. It was perfect for storing all kinds of temporary files as it was extremely fast and would be cleared every time the system rebooted. Windows doesn’t have anything like that.

I found a way to make something similar. I use a temporary folder on a hard drive. It’s not as fast as RAM but it is cleared on reboot by having the following script run at shutdown:

rmdir /S /Q g:\temp mkdir g:\temp

Basically delete the directory recursively and re-create it. Simple but effective. You can assign a drive letter to the directory too.

By mojo | Posted in windows | Comments (0)

BBC Master Compact keyboard pinout

16/05/2010 – 23:42

I’m working on a project involving the keyboard from a BBC Master Compact. I couldn’t find an accurate pinout on the web anywhere so I got my multimeter out and mapped it.

 LED Power     01 - 02       Column
 Row           03 - 04       Break
 Row           05 - 06       Row
 Column        07 - 08       Row
 Column        09 - 10       Column
 Column        11 - 12       Column
 Column        13 - 14       Column
 Column        15 - 16       Column
 Column        17 - 18       Column
 Row           19 - 20       SHIFT+CTRL
 Row           21 - 22       Column
 LED Caps      23 - 24       Column
 LED Anode     25 - 26       LED Shift Lock

The LEDs all have suitable resistors on them and can run directly from 5V. Break is pulled up by the same line as the power LED uses for 5V so is effectively on it’s own row. Inside the BBC it is used to trigger a hardware interrupt IIRC.

The SHIFT+CTRL pin (20) is special. These two keys use diodes that allow them to be read by pulling lines 21 (SHIFT) and 24 (CTRL) low in turn.

EDIT: Made some minor corrections

By mojo | Posted in hardware | Comments (0)

Bliss Box violating my copyright, GPL and more

13/05/2010 – 17:26

I just spotted this:

http://spawnlinux.dyndns.org/Bliss-Box/technical.html

It violates my copyright on some of the images such as the schematic and connector diagrams. It also violates the GPL by using V-USB and not publishing the relevant code. Chances are it probably uses some of my GPL’ed code, and the author admitted that it is based off some of Ralph’s code too (also GPL).

I emailed the guy but he is refusing to give any attribution, publish anything or provide any links back to the relevant sites.

Since he used his own server in dyndns I tracked him back to somewhere in Florida, using Warner Cable via Road Runner. I have sent complains to both of them.

By mojo | Posted in Internet, electronics, law | Comments (0)

CD32 pad support added to the Retro Adapter

09/05/2010 – 19:14

Just finished adding support for CD32 gamepads to the Retro Adapter firmware. I discovered a couple of interesting points.

1. The logic ICs used are really slow. I need a 75μs delay after the latch line changes before starting the clock and approximately 50μs before reading on every clock cycle. The shift register is a 74LS165 and the datasheet (from 2000 so ~8 years after of the CD32) says it will run at 20MHz with propagation delays in the low tens of nanoseconds. I suppose performance must really have improved in the 90s, or C= used low performance ICs, or there is some issue with the PCB/wiring capacitance.

2. The controller is not nearly as bad as I remember it. It’s no Saturn pad but it works reasonably well and the D-pad is similar to Sega ones. It’s better than a NES pad anyway.