dacs.doc electric

Random Access
December 2001

Jim Scheef, moderator

 

Members who are unable to attend the General Meeting may submit questions to askdacs@aol.com -- they will be presented at the meeting, and the response(s) will be placed in the Random Access column.

Q. I have a PC and my friend has a Mac. He sends me PhotoShop images, and I get a question: Do you want the resource fork or the data fork? Sometimes I can open up the data fork, sometimes I can’t open either. What is this all about?

A. Macs keep information about what a PC calls data file in a separate file called the ‘resource’ fork. The resource information contains the ‘intelligence’ as to what the file content is--what is usually implied by the ‘file extension’ in PCs, but much more. Your friend needs to save the image as a file type that is common to the PC--such as a TIFF or GIF or EPS or JPG etc. Because he is using the native PhotoShop save which doesn’t necessarily have an ‘extension,’ the Mac doesn’t know that it has to be formatted in a file format and with an extension that a PC will understand. Within PhotoShop or Finder there is a way to "Save as IBM PC format file." Then send ONLY the data fork.

Q. I’ve had Windows 98--when I do Start/Shutdown--I get a blank screen, then that Windows is shutting down - but it never completes the shutdown process.

A. The underlying problem is that a device driver is not getting the message to close from Windows. Often this is a background process or a device driver such as a sound card. Another common cause is some anti-virus programs can hang--especially Norton Anti-Virus and McAfee VirusScan, which often try to check a non-existent floppy diskette. It can be caused by such a simple thing as the sound card trying to play the shutdown wave file but not finding it! A search at Google (www.google.com) on the string ‘windows 98 shutdown hang’ found 7,000+ entries, but the first one, from Microsoft, looks the most promising--it includes a link to a Windows 98 patch which might cure the problem. Windows 98 also expects machines with ATX motherboards to respond to a power down command, but non-ATX machines don’t know what to do with it.

Q. Have people been having problems getting into SNET’s DSL using MS Internet Explorer during the last few days?

A. While no one reported chronic problems, there had been a few bumps. There were a lot of recommendations that you make sure that you have a personal firewall installed and up-to-date anti-virus software running. Once in a while you may find it necessary to re-boot the modem--especially with SNET, since they use PPoE with dynamic IP addressing. Lastly, check at www.cert.org--check that the modem you are using is not ‘hackable.’

Q. In Windows 2000, if I change a file’s data, close the application, and try to rename the folder, I get a sharing violation. Control/Alt/Delete does not show any running programs.

A. Do you have an automatic data backup applications running? For example, Disk Keeper from PowerQuest, or SafeGuard from McAfee may be making a copy of the file for you.

Q. I am trying to reduce the number of programs that start when the machine boots. I have emptied the Start/Programs/ StartUp folder--but I still get a lot of applications in the System Tray.

A. These things are often started from the Windows Registry, or for older applications, from the WIN.INI file. Either way, you must take care in how you stop them as you could prevent the machine from booting. For Windows 98 and newer, there is a utility in Start/Applications/System Tools called MSCONFIG which you can use to deactivate applications. Alternatively, there is a freeware utility you can download, StartStop, from www.tfi-technology.com/startstop.htm which will work with all 32-bit versions of Windows - 95, 98, 98SE, Me, 2000 and XP. It gives you the option of permanently disabling without uninstalling, or having the system prompt you when you boot, or let it run.

Q. I have a JPEG that has been damaged; is there a viewer that can let me get into the file so I can recover what is left?

A. The structure of a JPEG file is that it stores the dimensions of the image, author information if present, etc., in a header, followed by the color encoding table. The color encoding table says, for example, that color 1 is black, color 2 is a particular shade of blue, color 3 is a slightly different shade of blue, etc. The table will be unique for each file. If that table is damaged or missing, then the entire file will be unreadable and unsalvageable. It sounds like your file was destroyed by one of the viruses, such as Melissa, which infected image files by putting the virus code into the first thousand (or so) bytes of the file--thereby destroying it. The data is gone.

Q. I am going to upgrade a PC. I have picked out a motherboard and am thinking of a 1.4GHz AMD Thunderbird or a fair amount of money to go to a 1.6GHz processor. I will put a lot of RAM in since it is so cheap.

A. A 1.4GHz processor can actually outperform a 1.6GHz processor if the bus speed is faster. So take a good look at the front side bus speed (FSB rating.) On machines of this range, a very fast video card will also give you better perceived performance. Similar can be said of faster hard drives--you want to achieve a good balance.


Jim Scheef is the Mad Scientist at Telemark Systems Inc. where he develops custom software using Visual Basic and SQL Server and provides networking services using Windows NT/2000. He has been a DACS member since the day DOG became WC/MUG..

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