Ask Rick 200 14/04/12
I run a digital camera group for U3A using
Photoshop to manipulate photos. As some of the group now use RAW our existing
computer (5 years old) struggles to cope and takes a long time to respond. Could you please advise as to what
specification to look for in a replacement?
Alan Bishop, Ambleside
RAW file mode, available on many mid-market and
high-end digital cameras, is often compared to unprocessed film, meaning that
virtually no changes are made to the data produced by the camera’s image
sensor, which can affect quality and cannot be undone. However, since RAW files
undergo little or no compression they can be very large and put a real strain
on a PC’s resources. Even new high-spec models can find them hard going. There
are no magic numbers or must-have brands; the simple rule of thumb is to get a
machine with the fastest CPU, the most RAM and the biggest hard drive that your
budget allows. Of course, you could always ask your group to stick with
conventional, best-quality JPEGs for general photography and routine editing,
and save RAW mode for special occasions or where the extra information
contained in the files might make a visible difference to the end product.
Pop Up Puzzle
I live in a block of flats and connect to the
web using a wireless connection. My router is security enabled but can someone
in another flat utilise my signal via their laptop? If so, is this legal? The
reason for asking is that for some time now when I am on the web, I get a
mystery pop-up message that states ‘I am now connected’.
David Main, by email
That pop-up is almost certainly nothing to
worry about. It usually means the connection is being interrupted, possibly due
to poor signal strength, congestion or interference from other wireless
networks in the vicinity. This forces your router to channel hop, resulting in
a brief loss of connection. The security systems used on home wireless systems
can be hacked but it’s not an easy matter and requires a fair amount of
technical expertise and determination. Provided you are using the highest level
of encryption (usually WPA2), with a long passphrase of 25 or more characters,
you should be reasonably safe.
Hacking into a computer network is illegal (Computer
Misuse and Communications Acts of 1990 and 2003). One easy way to check if it
is happening to you is to observe your router’s activity lights when your PC is
switched off. An occasional blink is normal but if it is flashing constantly
then you should be suspicious. You may be able to identify the intruder with a
small freeware utility called ZamZom (http://goo.gl/BHg5A),
which shows the IP address, MAC address and the name of the computers and
devices connecting to your router.
Incidentally, you can stop wireless hackers in
their tracks using a feature on most routers called the DCHP Client List. This
lets you specify the unique MAC address of the PCs and other devices that you
want to allow to access your network and Internet connection. You should find
details of how to use it in your router’s manual or on-line help.
On two occasions recently my credit card has
not been recognised by a website. The card provider says there is no problem at
their end and no attempt was made to take money for the sale. They say it is a
website problem. Can you give me any further information and suggest how to
avoid this in future?
B R Colbourne, by email
Assuming your card is okay and works normally
in shops and petrol stations and so on then it is probably something quite
simple. You can obviously expect a rejection for any error when entering your
card number, security code and expiry date, but these days the extra measures
taken to prevent fraud has resulted in online payment forms becoming painfully
pedantic. The information you enter has to perfectly match the details held by
the credit card company – double check your postcode -- and even something as
innocuous as a space in a card number or a full stop after an initial can cause
Time for New PC?
The time and date on my computer are no longer
accurate. I think this suggests that there is a problem with a battery on the
processor board. The computer is only 4 years old so I am a little surprised by
this. My question is should I start to think about a new computer or replace
the processor board? If I choose the latter what issues am I likely to
encounter such as BIOS problems?
Roy Ward, by email
You are almost certainly right and the clock
backup or CMOS battery, which keeps the motherboard clock module ticking when
your PC is switched off, has almost certainly expired. They don’t last forever,
4 or 5 years is fairly typical, but there’s no need to replace your PC or the
motherboard. Clock batteries are widely available; they only cost a pound or
two and normally only take a few minutes to fit. It does, however, entail
removing the lid, and on some machines the battery in awkwardly placed, or
hidden behind a rat’s nest of cables, so if you are not confident of your
abilities have it seen to by an expert. If you fancy having a go yourself there
are plenty of tutorials on the web or take a look at this YouTube video (http://goo.gl/FdJsP), which gives you a good
idea of what is involved.
I will shortly be visiting Canada and taking my
iPad for communications and games etc. How do I charge it whilst there? They
have 120 volts mains, whilst we use 240 volts; as the voltage is lower do I
need a special piece of kit to make it work?
Hazel Barnard, by email
Don’t worry, nowadays virtually all
adaptors/chargers are universal and designed to work on a 100 to 240 volt,
50/60Hz supply. There should be a label or markings to that effect on the
charger and all you need to take with you is a North American mains plug
© R. Maybury 2012 2603