| Last
Month….
We entered the world of
virtual computer systems courtesy of Barry Gilchrist. This was
certainly an area that was new to me and I expect, to many of
the members around the table. So what is a virtual computer?
Barry explained that to
understand virtual computers, they have to be put in context with
the real thing. A physical computer is in essence a piece of hardware
that is a multifunctional device which when software is loaded
on, it can run programmes. The virtual computer is a temporary
computer simulated by software and resident in the physical machine.
Hence if a computer can run a piece of software such as Microsoft
Office under an operating system such as Windows XP, which incidentally
is also a piece of software, there is no reason why XP cannot
run within another copy of XP, and this is essentially what a
virtual computer is all about.
So there you have it, virtualisation
allows you to run multiple operating systems on one machine. As
Barry stated something almost for nothing! Now this is not a recent
idea and has been around a very long time and has its roots in
the old main frame industrial computers, some of which may be
familiar to you.
VAX/VMS … Virtual Address Extension/Virtual Memory System
VM/CMS … Virtual Machine/Conversational Monitoring System
Barry explained that during
the 1980’s and 90’s more time was spent developing
individual PCs and Servers. It was more cost effective than to
have a desktop PC than investing in large main frame computers.
As larger applications were developed and became more critical
to an operation, companies tended to place individual applications
on a dedicated Server so other applications were not affected
if a problem occurred. The consequence of this was to drive up
computer hardware costs and cause problems with the management
of so many machines.
VMWARE, seeing the problem,
went back to the original virtual ideas, producing a system based
on x86 architecture to run on a desktop computer or server. This
had its problems where many of the instructions had to be modified
so that the host computer did not take offence and fall over.
Once this problem was overcome, the virtual computer becomes a
tightly isolated machine resident within its host. This virtual
machine will behave exactly like its host, having its own virtual
(software based) RAM, Hard Disk space and Network Interface Card.
Any machine that interacts with the virtual machine will not be
aware that the machine is not a physical box. In fact this is
exactly what the end users want – the ability to run many
virtual machines that work identically to real machines. Barry
explained that a number of software houses now offer the software,
VMWARE and Microsoft’s Virtual PC are two of the most popular
available.
At this point, Barry powered
up his system and showed us a virtual machine running XP pro.
He explained that it could be a little slow loading up but when
running, you could not tell which operating system was the original.
The virtual PC sits in its own folder. The one excellent feature
and one that Barry uses as a software development engineer is
that when you shut down the virtual machine everything on it is
lost. Hence, a great way to test dodgy software etc without compromising
your original system. There are facilities of course to save anything
you wish to retain if you are happy with it. As Barry said, a
lot of time and heartache can be saved by using a virtual computer
in his line of work. But this was not all, he also showed the
virtual machine linking up to the internet which needed a bit
more thought and control but still performed perfectly once configured.
Again, a great way to test suspicious websites as everything is
cleared out when you shut the virtual machine down.
So after an impressive
demonstration, Barry explained that the virtual PC file size required
for XP Pro was around 4Gb while Vista requires something like
8Gb. In terms of cost effectiveness, a company buying 2 large
PC servers and perhaps 20 operating systems would be much cheaper
than buying 20 or more individual machines.
Our thanks to Barry for
giving us an insight into an interesting area of computer which
I suspect few of us have ventured into. I am sorry not to have
included all the technical detail but if this has whetted your
appetite for more, I am sure Barry will be happy to help you.
Dave Robb
2008
Photo Competition
Don’t forget that
next month is our annual photographic competition. Below is a
list of the topics, I am sure you must have something that will
fit into several of these categories.
We again are lucky to have Arthur Payne as our guest judge. So
lets have a bumper entry for him to judge.
Travel,
Landscape/seascape,
Still Life,
Nature,
Architectural.
Portrait.
Antivirus XP
You may have been unlucky
enough to have seen a popup come up on your screen. The message
that it brings is that your computer has multiple infections and
it persistently suggest that you should download Antivirus XP
2008 or 2009 in order to fix the problem.
The software appears to find and remove multiple Trojans and viruses
but, in fact, does absolutely nothing.
This fake software offer comes from Russia but not with Love.
It has proved a nice little earner, it is thought that this Russian
hacker has pocketed $ 158,000 in just a week. So beware of all
of this type of message.
Adobe Reader 8 Security
Issues
Adobe has released version
8.1.3 of Adobe Acrobat and the free Acrobat Reader to close eight
security holes. Some of the holes allow attackers to install code
into a computer and execute it via specially created PDF documents.
The current versions 9.x of Acrobat and Reader for Windows and
Mac are not affected. Therefore, Mac and Windows users can either
switch to version 9 or update to 8.1.3.
Microsoft Discontinues Windows... 3.x
You may have thought that
Windows 3.x has been dead and buried for a long time. It has in
fact been living a secret life onboard aircraft as the embedded
operating system that powers the in-flight entertainment systems
on some Virgin and Qantas long-haul jets.
As of 1st November 2008 Microsoft has stopped issuing licences
for Windows 3.x, which debuted in May 1990.
It will be interesting to see how long some of the newer Operating
systems continue to be used in similar special roles.
Derek
Christmas Dinner 2008
A final reminder that we
have booked the Bowls club Restaurant for Thursday Evening December
18th.
Ben has kindly offered
to organise it again for us and by the time you read this, you
should hopefully have received an email regarding orders.
The meal is a three course
affair plus coffee & mince pies and cost £10.95. We
ask that you also include a £1.00 tip per person for the
tip.
Please send your orders
to Ben at benbarretto@talktalk.net .
He requires your choices for starter, main and sweet.
Money can be given to Ben
at the meetings. Please make cheques payable to “The Clubhouse
Restaurant”
You will find the menu
on the back page of this newsletter.
Christmas Menu
1. Tomato and Basil Soup
2. Prawn Cocktail
3. Breaded Brie Wedges
4. Chicken Wings
5. Lime and Coriander Salmon
Wedges
1. Chicken Breast Fillet with Mushroom Sauce
2. Roast Beef with all
the Trimmings
3. Roast Turkey with all
the Trimmings
4. Salmon Hollandaise
5. Leek and Mushroom Crumble
1. Selection of Cold Sweets
2. Xmas Pudding
Coffee and Mince Pies
Cost of the meal is £10.95
(please include a £1.00 tip per person)
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