Planet MarZ

Wednesday, April 30, 2008

1. Ask yourself, "Am I important to this company? Will it pain the boss to see me go?" If the answer is "no," expect to lose your job and have a backup job in mind.
2. Is the girl your superior? If so, then forget about it. Unless she has shown incontrovertible interest in you, this should remain a fantasy. A number of things could go wrong with this scenario.
3. Does she like you? Be very honest with yourself when it comes to this question. Does she ever come over to your desk to chat? Does she wink at you or blush when you're around? If not, then a date is best not pursued.
4. Okay so we have established that you like her, she likes you, you're both either indispensable or don't care too much about your jobs. Time to ask her out. Remember her interests and pick out a good first date: dinner, a movie, a concert, a sporting event, etc. You want it to be just the two of you, but whatever you do, make it sound casual and ambiguous. Another idea is to ask her to coffee or dessert after an evening work function. Make sure you don't do this in front of any other coworkers. Your somewhat official sounding date must be kept secret from gossipers.
5. If she says "no," give up. It's not worth it. Keep all of your future interactions business-related. If she says yes, congratulations! You've started a relationship that could harm one or both of your careers.

Tips

- Make sure she's worth it.

- Make sure your coworkers don't find out.

- Don't stand too close to each other at work.

- Don't talk to each other in a lovey-dovey way.

- Don't make other coworkers feel uncomfortable around the two of you.

- Otherwise, gossip will spread and dreaded talks with management will ensue.

- Do not use the company email! If it is monitored or if you are caught, you will get fired. It can be used as evidence against you in a sexual harassment case as well.

- It is standard for dating at work to be against company policy. You may get fired or asked to leave.

- If you ask a girl out and she gets uncomfortable, you may be fired or sued for sexual harassment. Read your company's policy thoroughly.

posted by Marvstyles
9:56 PM
0 comments

1. Be mature. When she's passing you in the hallway, don't keep talking to your best friend about Pokemon, talk about something mature such as a team you might be in, a book you might have recently read, something you know someone her age would be interested in.
2. Be conscious about your appearance. If you're playing with your GameBoy and smell like you haven't taken a shower in 2 days, you had better hope that she doesn't notice you. Make sure to wear cologne(but not too much), comb your hair and focus on making yourself as good-looking as possible. If you don't know what cologne to get, have a girl that's a friend help you. If you don't have one, the gay dude at Macy's can help you pick one out. No offense, but if straight guys bought their own cologne we'd all smell like bacon and diesel fuel.
3. Try to look as tall as you possibly can. Sorry to short guys, but taller guys usually have an easier time with a girl's attention. Put your chest out(it shows confidence), and try to put yourself in a position where you look like the center of everything.
4. Join an activity she is in and/or might be interested in. If she is in a debate team, joining the team and looking smart will get her to respect you.
5. Don't be ashamed to ask her out. This is a sure way to prove you're more mature than you look.

Tips

-Attracting an older girl requires the exact same skills as getting a girl your age; you just have to be better at them.

-Be aware she might like you but she might have a problem dating a younger guy because her classmates and friends might make fun of her.

-When you talk to her, don't try to sound smarter than you would normally be at your age, it will make you look like an idiot.

-There's ALWAYS a friend of hers that everybody can read like a book.Ask her friend questions that can help you.

-Confections can be hard. DON'T ASK HER IMMATURE QUESTIONS LIKE:"WILL YOU BE MY GIRLFRIEND?"(I GUESS YOU KNOW THAT,BUT I MUST REMIND YOU)You can talk to her friend that can help and you trust.

-Don't ever do anything immature in front of her, such as playing some video game (unless she's into video games), laughing with your buds about some dumb joke, or picking your nose. Don't, however, pretend to be someone you're not, or pretend to like things that you don't. They come back to bite you.

-If you do join a team she's interested in, you may want to acquire the skills to do well on that team. If you fumble at each question/debate/[insert possible obstacle here], you won't gain her respect at all.

-Don't tell her friend anything,because you're not the only one who can read her like a book.

posted by Marvstyles
12:12 AM
0 comments

Wednesday, April 23, 2008

What should you do in the first five minutes after you discover your computer has been hacked?

Sitting at your desk, you notice some odd activity in a log while you're looking into a user problem. The more you step through it, the more you are convinced that something is just not right. Your heart skips a beat when you realize that the system has been hacked.

At this point, you enter a stage of shock as you ask yourself, "How could this happen?" and "What do I do now?"

Although you'll find plenty of advice on how to keep your systems from being hacked, there are relatively few articles that will help you sort things out in the aftermath of an attack. So for the next three weeks, I'll present a series of articles that will explain what you should do in the first five minutes, in the first hour, and in the first week after you've discovered that an interloper has compromised your systems. This article will focus on the most immediate actions you must take to secure your system: evaluate, communicate, and disconnect.

Evaluate
The first question that you must answer after an attack (or preferably before) is what your objectives are. In most cases, the objectives are simple: prevent further intrusion and resolve the problem. However, in some cases, you will want to be able to positively identify the intruder and, in others, you will be focused on figuring out which vulnerability the hacker exploited.

Identify the intruder
It may be necessary to positively identify the intruder so that you can refer the matter to the police for further investigation and possible prosecution. Of course, this is not the most expedient way to get the systems back online and prevent further infection. Identifying intruders can be difficult, particularly if they have covered their tracks well. Despite Hollywood's portrayal of hackers easily being traced, someone who is routing traffic through several systems is not only difficult to find, but might be -- in all practical terms -- impossible to track down.

Identify the vulnerability
Another approach that some organizations take is to try to identify the specific vulnerability exploited. The thinking is that you want to patch the specific hole that allowed this intruder to gain access. By and large, this approaches the problem from a suboptimal perspective. A far better strategy is to attempt to identify all vulnerabilities and prevent any intruder from gaining access to your systems, rather than focusing on the one vulnerability this particular hacker exploited.

Many of today's security assessment tools will allow you to quickly test and resolve all vulnerabilities.

Return systems to operation
If this is the first time you have been attacked, you may find it simpler to forgo trying to pinpoint the intruder or the specific vulnerability that was exploited. In general, it is unlikely that you will be able to easily generate the logs you might need to target the origin of the intrusion.

Patching the vulnerabilities and returning systems to operation as soon as possible is the most straightforward approach. It reduces your risk and allows you to fortify your defences without worrying about the intruder continuing to take advantage of your systems.

Plan ahead
In many cases, organizations determine their course of action prior to an attack. But in an equal number of cases, organizations must make this their first order of business after an attack. In addition to determining your specific goals after an attack, you should consider executing a disaster recovery plan, if one exists for your organization. Depending on the severity of the situation, it may make sense to treat the situation as if the data center had been destroyed.

The one unique complication to activating a disaster recovery plan for an organization is that it is typically centred on a known event with a known time. But with an intrusion into your network, you may not know exactly when the system was first compromised. This can complicate the recovery process because it may not be clear what set of backups should be restored for each system. Further complicating matters is the fact that some systems may have been compromised before others, so it may be necessary to repeat the restoration process several times while trying to determine when the first intrusion occurred and on which system.

Communicate
Once you have decided on your approach, you need to communicate to upper management what is happening -- or what you suspect is happening. This is perhaps the most difficult step and, because of that, it is one that is often skipped or delayed. But despite the potential for internal political problems, it is important to let business leadership understand what is happening so that everyone can plan for the steps required to resolve the problem. It will also give business leadership an opportunity to reaffirm the goal for problem resolution, whether that goal is to go after the intruder, target the vulnerability, or simply solve the problem as quickly as possible.

You should also communicate with your IT peers about the problem. You need everyone on the team to look for suspicious activity to ensure that the network is not further compromised. To that end, the more professionals involved who are aware of the problem, the more likely it is that nothing will slip through the cracks and be missed.

Conversely, you should not communicate with your users that you have detected an intrusion. An employee may have caused the breach, either by providing a password to a friend with the intention of allowing a breach or through something more innocent. It is a good idea to hold off on notifying employees until the HR department can communicate the company policy along with the message.

Finally, if you have a security infrastructure partner, communicate with it immediately that you have a potential situation. Even if you have only engaged the organization in the past to perform a security audit, you should call it to indicate that you suspect that you have a problem. The intent here is not at this point to ask for help but rather to inform the partner so that it can be prepared to assist if necessary.

Disconnect
If you are not planning on attempting to identify the intruder or the vulnerability, you should disconnect the system or the entire internal network from the Internet as soon as possible. This prevents the intruder from working against you as you try to clean up the mess and also prevents further infections or data loss while you work on the systems.

One of the downsides of disconnecting is that people who want to use the system internally and externally will be unable to do so until the problem is resolved. This can exert substantial internal pressure to take shortcuts to get the systems back up again. But the natural desire to reconnect systems before a thorough evaluation of their status has been conducted is ill advised and typically leads to repeated intrusions while the problems with each of the servers are identified and resolved one-by-one.

The decision to disconnect the entire organization from the Internet or to disconnect just one system or a few systems is a difficult call, particularly in the first five minutes. You will not have had time to evaluate which, if any, other systems have been compromised, so it is possible that removing a single system from the Internet may not resolve the problem. On the other hand, you may want the organization to continue to function with as little disruption as possible.

Ultimately, the decision comes down to one of risk tolerance. How much risk is the organization willing to accept to avoid some downtime? In most organizations, the risk of potential intruders greatly outweighs the desire to maintain availability of all systems. In other words, most organizations agree that it is important to disconnect from the Internet immediately so that the systems can be checked for signs of intrusion without the possibility of intruders attempting to cover their tracks.

Conclusion
The first few minutes after you discover an attack are likely to be stressful and confused, so it's important to have a plan of action in place before it happens. When you realise you've been attacked, make sure you identify your objectives in resolving the situation, communicate the situation promptly to business leadership and peers, and determine whether the problem requires you to disconnect one or more systems from the Internet. Deciding how to react to an attack is tricky, at best. The actions you take (or don't take) can have a huge impact on your organisation -- and on your reputation. However, following a plan for controlling the situation can make things less chaotic and start you down the right path to get things back on track.

posted by Marvstyles
11:38 PM
0 comments

CAM
A cam is a theater rip usually done with a digital video camera. A mini tripod is sometimes used, but a lot of the time this wont be possible, so the camera make shake. Also seating placement isn't always idle, and it might be filmed from an angle. If cropped properly, this is hard to tell unless there's text on the screen, but a lot of times these are left with triangular borders on the top and bottom of the screen. Sound is taken from the onboard microphone of the camera, and especially in comedies, laughter can often be heard during the film. Due to these factors picture and sound quality are usually quite poor, but sometimes we're lucky, and the theater will be fairly empty and a fairly clear signal will be heard.

TELESYNC (TS)
A telesync is the same spec as a CAM except it uses an external audio source (most likely an audio jack in the chair for hard of hearing people). A direct audio source does not ensure a good quality audio source, as a lot of background noise can interfere. A lot of the times a telesync is filmed in an empty cinema or from the projection booth with a professional camera, giving a better picture quality. Quality ranges drastically, check the sample before downloading the full release. A high percentage of Telesyncs are CAMs that have been mislabeled.

TELECINE (TC)
A telecine machine copies the film digitally from the reels. Sound and picture should be very good, but due to the equipment involved and cost telecines are fairly uncommon. Generally the film will be in correct aspect ratio, although 4:3 telecines have existed. A great example is the JURASSIC PARK 3 TC done last year. TC should not be confused with TimeCode , which is a visible counter on screen throughout the film.

SCREENER (SCR)
A pre VHS tape, sent to rental stores, and various other places for promotional use. A screener is supplied on a VHS tape, and is usually in a 4:3 (full screen) a/r, although letterboxed screeners are sometimes found. The main draw back is a "ticker" (a message that scrolls past at the bottom of the screen, with the copyright and anti-copy telephone number). Also, if the tape contains any serial numbers, or any other markings that could lead to the source of the tape, these will have to be blocked, usually with a black mark over the section. This is sometimes only for a few seconds, but unfortunately on some copies this will last for the entire film, and some can be quite big. Depending on the equipment used, screener quality can range from excellent if done from a MASTER copy, to very poor if done on an old VHS recorder thru poor capture equipment on a copied tape. Most screeners are transferred to VCD, but a few attempts at SVCD have occurred, some looking better than others.

DVD-SCREENER (DVDscr)
Same premise as a screener, but transferred off a DVD. Usually letterbox , but without the extras that a DVD retail would contain. The ticker is not usually in the black bars, and will disrupt the viewing. If the ripper has any skill, a DVDscr should be very good. Usually transferred to SVCD or DivX/XviD.

DVDRip
A copy of the final released DVD. If possible this is released PRE retail (for example, Star Wars episode 2) again, should be excellent quality. DVDrips are released in SVCD and DivX/XviD.

VHSRip
Transferred off a retail VHS, mainly skating/sports videos and XXX releases.

TVRip
TV episode that is either from Network (capped using digital cable/satellite boxes are preferable) or PRE-AIR from satellite feeds sending the program around to networks a few days earlier (do not contain "dogs" but sometimes have flickers etc) Some programs such as WWF Raw Is War contain extra parts, and the "dark matches" and camera/commentary tests are included on the rips. PDTV is capped from a digital TV PCI card, generally giving the best results, and groups tend to release in SVCD for these. VCD/SVCD/DivX/XviD rips are all supported by the TV scene.

WORKPRINT (WP)
A workprint is a copy of the film that has not been finished. It can be missing scenes, music, and quality can range from excellent to very poor. Some WPs are very different from the final print (Men In Black is missing all the aliens, and has actors in their places) and others can contain extra scenes (Jay and Silent Bob) . WPs can be nice additions to the collection once a good quality final has been obtained.

DivX Re-Enc
A DivX re-enc is a film that has been taken from its original VCD source, and re-encoded into a small DivX file. Most commonly found on file sharers, these are usually labeled something like Film.Name.Group(1of2) etc. Common groups are SMR and TND. These aren't really worth downloading, unless you're that unsure about a film u only want a 200mb copy of it. Generally avoid.

Watermarks
A lot of films come from Asian Silvers/PDVD (see below) and these are tagged by the people responsible. Usually with a letter/initials or a little logo, generally in one of the corners. Most famous are the "Z" "A" and "Globe" watermarks.

Asian Silvers / PDVD
These are films put out by eastern bootleggers, and these are usually bought by some groups to put out as their own. Silvers are very cheap and easily available in a lot of countries, and its easy to put out a release, which is why there are so many in the scene at the moment, mainly from smaller groups who don't last more than a few releases. PDVDs are the same thing pressed onto a DVD. They have removable subtitles, and the quality is usually better than the silvers. These are ripped like a normal DVD, but usually released as VCD.

Formats

VCD
VCD is an mpeg1 based format, with a constant bitrate of 1150kbit at a resolution of 352x240 (NTCS). VCDs are generally used for lower quality transfers (CAM/TS/TC/Screener(VHS)/TVrip(analogue) in order to make smaller file sizes, and fit as much on a single disc as possible. Both VCDs and SVCDs are timed in minutes, rather than MB, so when looking at an mpeg, it may appear larger than the disc capacity, and in reality u can fit 74min on a CDR74.

SVCD
SVCD is an mpeg2 based (same as DVD) which allows variable bit-rates of up to 2500kbits at a resolution of 480x480 (NTSC) which is then decompressed into a 4:3 aspect ratio when played back. Due to the variable bit-rate, the length you can fit on a single CDR is not fixed, but generally between 35-60 Mins are the most common. To get a better SVCD encode using variable bit-rates, it is important to use multiple "passes". this takes a lot longer, but the results are far clearer.

XVCD/XSVCD
These are basically VCD/SVCD that don't obey the "rules". They are both capable of much higher resolutions and bit-rates, but it all depends on the player to whether the disc can be played. X(S)VCD are total non-standards, and are usually for home-ripping by people who don't intend to release them.

DivX / XviD
DivX is a format designed for multimedia platforms. It uses two codecs, one low motion, one high motion. most older films were encoded in low motion only, and they have problems with high motion too. A method known as SBC (Smart Bit-rate Control) was developed which switches codecs at the encoding stage, making a much better print. The format is Ana orphic and the bit-rate/resolution are interchangeable. Due to the higher processing power required, and the different codecs for playback, its unlikely we'll see a DVD player capable of play DivX for quite a while, if at all. There have been players in development which are supposedly capable, but nothing has ever arisen. The majority of PROPER DivX rips (not Re-Encs) are taken from DVDs, and generally up to 2hours in good quality is possible per disc. Various codecs exist, most popular being the original Divx3.11a and the new XviD codecs.

CVD
CVD is a combination of VCD and SVCD formats, and is generally supported by a majority of DVD players. It supports MPEG2 bit-rates of SVCD, but uses a resolution of 352x480(ntsc) as the horizontal resolution is generally less important. Currently no groups release in CVD.

DVD-R
Is the recordable DVD solution that seems to be the most popular (out of DVD-RAM, DVD-R and DVD+R). it holds 4.7gb of data per side, and double sided discs are available, so discs can hold nearly 10gb in some circumstances. SVCD mpeg2 images must be converted before they can be burnt to DVD-R and played successfully. DVD>DVDR copies are possible, but sometimes extras/languages have to be removed to stick within the available 4.7gb.

MiniDVD
MiniDVD/cDVD is the same format as DVD but on a standard CDR/CDRW. Because of the high resolution/bit-rates, its only possible to fit about 18-21 mins of footage per disc, and the format is only compatible with a few players.

Misc Info

Regional Coding
This was designed to stop people buying American DVDs and watching them earlier in other countries, or for older films where world distribution is handled by different companies. A lot of players can either be hacked with a chip, or via a remote to disable this.

RCE
RCE (Regional Coding Enhancement) was designed to overcome "Multiregion" players, but it had a lot of faults and was overcome. Very few titles are RCE encoded now, and it was very unpopular.

Macrovision
Macrovision is the copy protection employed on most commercial DVDs. Its a system that will display lines and darken the images of copies that are made by sending the VHS signals it can't understand. Certain DVD players (for example the Dansai 852 from Tescos) have a secret menu where you can disable the macrovision, or a "video stabaliser" costs about 30UKP from Maplin (Code:
www.maplin.co.uk
)

NTSC/PAL
NTSC and PAL are the two main standards used across the world. NTSC has a higher frame rate than pal (29fps compared to 25fps) but PAL has an increased resolution, and gives off a generally sharper picture. Playing NTSC discs on PAL systems seems a lot easier than vice-versa, which is good news for the Brits icon_smile.gif An RGB enabled scart lead will play an NTSC picture in full colour on most modern tv sets, but to record this to a VHS tape, you will need to convert it to PAL50 (not PAL60 as the majority of DVD players do.) This is either achieved by an expensive converter box (in the regions of ?200+) an onboard converter (such as the Dansai 852 / certain Daewoos / Samsung 709 ) or using a World Standards VCR which can record in any format.

News Sites
There are generally 2 news sites, and I'm allowed to be biased icon_smile.gif For Games/Apps/Console :: isonews.com[ is generally regarded as the best, but for VCD/SVCD/DivX/TV/XXX vcdquality.com displays screen grabs and allows feedback. **NOTICE** neither site offers movie downloads, and requesting movies/trades etc on the forums of either is NOT permitted.

Release Files

RARset
The movies are all supplied in RAR form, whether its v2 (rar>.rxx) or v3 (part01.rar > partxx.rar) form.

BIN/CUE
VCD and SVCD films will extract to give a BIN/CUE. Load the .CUE into notepad and make sure the first line contains only a filename, and no path information. Then load the cue into Nero/CDRWin etc and this will burn the VCD/SVCD correctly. TV rips are released as MPEG. DivX files are just the plain DivX - .AVI

NFO
An NFO file is supplied with each movie to promote the group, and give general iNFOrmation about the release, such as format, source, size, and any notes that may be of use. They are also used to recruit members and acquire hardware for the group.

SFV
Also supplied for each disc is an SFV file. These are mainly used on site level to check each file has been uploaded correctly, but are also handy for people downloading to check they have all the files, and the CRC is correct. A program such as pdSFV or hkSFV is required to use these files.

Usenet Information

Access
To get onto newsgroups, you will need a news server. Most ISPs supply one, but this is usually of poor retention (the amount of time the files are on server for) and poor completition (the amount of files that make it there). For the best service, a premium news server should be paid for, and these will often have bandwidth restrictions in place.

Software
You will need a newsreader to access the files in the binary newsgroups. There are many different readers, and its usually down to personal opinion which is best. Xnews / Forte Agent / BNR 1 / BNR 2 are amongst the popular choices. Outlook has the ability to read newsgroups, but its recommended to not use that.

Usenet posts are often the same as those listed on VCDQUALiTY (i.e., untouched group releases) but you have to check the filenames and the description to make sure you get what you think you are getting. Generally releases should come down in .RAR sets. Posts will usually take more than one day to be uploaded, and can be spread out as far as a week.

PAR files
As well as the .rxx files, you will also see files listed as .pxx/.par . These are PARITY files. Parity files are common in usenet posts, as a lot of times, there will be at least one or two damaged files on some servers. A parity file can be used to replace ANY ONE file that is missing from the rar set. The more PAR files you have, the more files you can replace. You will need a program called SMARTPAR for this.

Scene Tags

PROPER
Due to scene rules, whoever releases the first Telesync has won that race (for example). But if the quality of that release is fairly poor, if another group has another telesync (or the same source in higher quality) then the tag PROPER is added to the folder to avoid being duped. PROPER is the most subjective tag in the scene, and a lot of people will generally argue whether the PROPER is better than the original release. A lot of groups release PROPERS just out of desperation due to losing the race. A reason for the PROPER should always be included in the NFO.

SUBBED
In the case of a VCD, if a release is subbed, it usually means it has hard encoded subtitles burnt throughout the movie. These are generally in malaysian/chinese/thai etc, and sometimes there are two different languages, which can take up quite a large amount of the screen. SVCD supports switch able subtitles, so some DVDRips are released with switch able subs. This will be mentioned in the NFO file if included.

UNSUBBED
When a film has had a subbed release in the past, an Unsubbed release may be released

LIMITED
A limited movie means it has had a limited theater run, generally opening in less than 250 theaters, generally smaller films (such as art house films) are released as limited.

INTERNAL
An internal release is done for several reasons. Classic DVD groups do a lot of .INTERNAL. releases, as they wont be dupe'd on it. Also lower quality theater rips are done INTERNAL so not to lower the reputation of the group, or due to the amount of rips done already. An INTERNAL release is available as normal on the groups affiliate sites, but they can't be traded to other sites without request from the site ops. Some INTERNAL releases still trickle down to IRC/Newsgroups, it usually depends on the title and the popularity. Earlier in the year people referred to Centropy going "internal". This meant the group were only releasing the movies to their members and site ops. This is in a different context to the usual definition.

STV
Straight To Video. Was never released in theaters, and therefore a lot of sites do not allow these.

ASPECT RATIO TAGS
These are *WS* for widescreen (letterbox) and *FS* for Fullscreen.

RECODE
A recode is a previously released version, usually filtered through TMPGenc to remove subtitles, fix color etc. Whilst they can look better, its not looked upon highly as groups are expected to obtain their own sources.

REPACK
If a group releases a bad rip, they will release a Repack which will fix the problems.

NUKED
A film can be nuked for various reasons. Individual sites will nuke for breaking their rules (such as "No Telesyncs") but if the film has something extremely wrong with it (no soundtrack for 20mins, CD2 is incorrect film/game etc) then a global nuke will occur, and people trading it across sites will lose their credits. Nuked films can still reach other sources such as p2p/usenet, but its a good idea to check why it was nuked first in case. If a group realise there is something wrong, they can request a nuke.

NUKE REASONS :: this is a list of common reasons a film can be nuked for (generally DVDRip)

** BAD A/R ** :: bad aspect ratio, ie people appear too fat/thin
** BAD IVTC ** :: bad inverse telecine. process of converting framerates was incorrect.
** INTERLACED ** :: black lines on movement as the field order is incorrect.

DUPE
Dupe is quite simply, if something exists already, then theres no reason for it to exist again without proper reason.

posted by Marvstyles
12:40 AM
0 comments

Tip #1
Upgrade your memory. Most users will see a distinct improvement in performance when they add more memory. You'll need to consult the vendor or the manual to know what sort of memory to buy but sites such as Crucial Technology will give you all the information you'll need. With prices around $36 for a 256MB 168-pin DIMM, you can afford to be generous. See Tip #10 for information about how to understand your system resource loading.

Tip #2
Clean your desktop. All those icons on the desktop can slow your system. You can safely delete icons that run programs by selecting one or more and pressing the delete key. Get into the habit of running programs from the Start Programs menu instead. XP users have a Desktop Cleanup Wizard to help them clean their desktop. It can be found in Control Panel, Display, Desktop, Customize Desktop.

Tip #3
Clean out unwanted programs. You have probably downloaded and installed several programs you no longer need. Like spring-cleaning your kitchen cupboard, you should clear out the rubbish. There is only one safe way to do this. Use the Add/Remove programs utility in Control Panel. Never try deleting folders directly.

Tip #4 Disk Cleanup Wizard
Clean out files no longer required. Your system is full of unneeded backup, log files and temporary files. Why not clean them out to create some disk space? The Disk Cleanup Wizard will do all this and will empty the Recycle bin as well. Just select Start Menu, Programs, Accessories, System Tools, Disk Cleanup. This great wizard calculates how much space you?ll save, and allows you to delete files by category. From the screen shot here, you can see that it will free a massive 23MB of disk space on my system.

Tip #5
Defragment your hard disk. Now you've freed up lots of disk space, the next step is to defragment your hard disk. As you write to your hard disk, it becomes more and more difficult to keep files stored together so a file may be split or fragmented, over several parts of the disk. This slows access to the files, causing the system to slow. Select Start Menu, Programs, Accessories, System Tools, Disk Defragmenter. Remember to disable any screen savers before defragmenting or it'll never finish.

Tip #6
Use a decent Antivirus tool. Viruses can slow your system quite significantly as well as cause damage to files. Use an Antivirus tool such as the free AVG.

Tip #7
Get rid of screen savers. They are not necessary and occupy resources.

Tip #8
Don't always rush to use the latest bloated software. For example, Office XP may have lots of bells and whistles but it's slower than the leaner versions of yesteryear.

Tip #9 Windows Task Manager
Be sure to use the latest drivers. Manufacturers often update the driver programs for your system components eg. for your graphics card. To identify the component use Control Panel, System, Hardware, Device Manager. To find the latest driver search on the component name using a good search engine such as Google.

Tip #10
Understand your system loading. The most common reason a Windows system slows down is when you've used every byte of physical memory (RAM) and Windows has to start paging which is to use your hard disk as extra virtual memory. As hard disk is much slower than physical memory your system will slow down. Knowing how close you are to paging will tell you whether you need more memory. With Windows XP, just press control, alt and delete keys together to start the Windows Task Manager. Do you see the Commit Charge at the bottom right corner? The first number is the total amount of physical and virtual memory in use. The second number is the total available. If the amount in use is greater than half the amount available, it may be time to increase the amount of memory on board.

Useful Tip - Go to Start, then Run, type in msconfig on the tabs at the top got to the one called StartUp disable any useless things that are enabled. Hit apply then restart the computer.

posted by Marvstyles
12:25 AM
1 comments

1) Make a new .txt document & open it in notepad.

2) Add this line (suit to your needs):
tree /a /f "c:\mp3" > "c:\mylist.txt"
(include quotation marks)

c:\mp3 - dir to list

/f - means also files will be written - omit this if you want to list only dirs

c:\mylist.txt - says where the list will be written & how its named.

3) Close notepad & rename the document to "list_music.bat" (without quotation marks) (any filename will do as long as the extension is .bat).

4) Double-click the .bat file & you'll get a nice looking list of the directories (and files) in a .txt file.

posted by Marvstyles
12:18 AM
0 comments

Monday, April 21, 2008

* The Benefits of Secondary Storage
Picture, if you can, how many filing-cabinet drawers would be required to hold the millions of files of, say, tax records kept by the Internal Revenue Service or historical employee records kept by General Motors. The record storage rooms would have to be enormous. Computers, in contrast, permit storage on tape or disk in extremely compressed form. Storage capacity is unquestionably one of the most valuable assets of the computer.

Secondary storage, sometimes called auxiliary storage, is storage separate from the computer itself, where you can store software and data on a semi permanent basis. Secondary storage is necessary because memory, or primary storage, can be used only temporarily. If you are sharing your computer, you must yield memory to someone else after your program runs; if you are not sharing your computer, your programs and data will disappear from memory when you turn off the computer. However, you probably want to store the data you have used or the information you have derived from processing; that is why secondary storage is needed. Furthermore, memory is limited in size, whereas secondary storage media can store as much data as necessary.

# The benefits of secondary storage can be summarized as follows:

* Capacity. Organizations may store the equivalent of a roomful of data on sets of disks that take up less space than a breadbox. A simple diskette for a personal computer holds the equivalent of 500 printed pages, or one book. An optical disk can hold the equivalent of approximately 400 books.
* Reliability. Data in secondary storage is basically safe, since secondary storage is physically reliable. Also, it is more difficult for unscrupulous people to tamper with data on disk than data stored on paper in a file cabinet.
* Convenience. With the help of a computer, authorized people can locate and access data quickly.
* Cost. Together the three previous benefits indicate significant savings in storage costs. It is less expensive to store data on tape or disk (the principal means of secondary storage) than to buy and house filing cabinets. Data that is reliable and safe is less expensive to maintain than data subject to errors. But the greatest savings can be found in the speed and convenience of filing and retrieving data.
These benefits apply to all the various secondary storage devices but, as you will see, some devices are better than others. We begin with a look at the various storage media, including those used for personal computers, and then consider what it takes to get data organized and processed.
# Magnetic Disk Storage
Diskettes and hard disks are magnetic media; that is, they are based on a technology of representing data as magnetized spots on the disk with a magnetized spot representing a 1 bit and the absence of such a spot representing a 0 bit.
Reading data from the disk means converting the magnetized data to electrical impulses that can be sent to the processor. Writing data to disk is the opposite: sending electrical impulses from the processor to be converted to magnetized spots on the disk. The surface of each disk has concentric tracks on it. The number of tracks per surface varies with the particular type of disk.



[Diskettes ]

Made of flexible Mylar, a diskette can record data as magnetized spots on tracks on its surface. Diskettes became popular along with the personal computer.
Figure 1: Diskettes
The older diskette, 5-1/4 inches in diameter, is still in use, but newer computers use the 3-1/2 inch diskette (Figure 1). The 3-1/2 inch diskette has the protection of a hard plastic jacket, a size to fit conveniently in a shirt pocket or purse, and the capacity to hold significantly more data than a 5-1/4 inch diskette. Diskettes offer particular advantages which, as you will see, are not readily available with hard disk:

* Portability. Diskettes easily transport data from one computer to another. Workers, for example, carry their files from office computer to home computer and back on a diskette instead of in a briefcase. Students use the campus computers but keep their files on their own diskettes.
* Backup. It is convenient to place an extra copy of a hard disk file on a diskette.
* New software. Although, for convenience, software packages are kept on hard disk, new software out of the box may come on diskettes (new software also may come on CD-ROM disks, which we will discuss shortly).

The end of the diskettes useful life-time may be upon us. In 1998 Macintosh introduced its new computer, the IMAC, without a floppy disk drive. Alternatives such as Zip disks (discussed later), or transferring data via networks are making the low-capacity diskette become obsolete.


Figure 1: Diskettes

Hard Disks
A hard disk is a metal platter coated with magnetic oxide that can be magnetized to represent data. Hard disks come in a variety of sizes.
Hard disk for mainframes and minicomputers may be as large as 14 inches in diameter. Several disks can be assembled into a disk pack. There are different types of disk packs, with the number of platters varying by model. Each disk in the pack has top and bottom surfaces on which to record data. Many disk devices, however, do not record data on the top of the top platter or on the bottom of the bottom platter.

A disk drive is a machine that allows data to be read from a disk or written on a disk. A disk pack is mounted on a disk drive that is a separate unit connected to the computer. Large computers have dozens or ever hundreds of disk drives. In a disk pack all disks rotate at the same time although only one disk is being read or written on at any one time. The mechanism for reading or writing data on a disk is an access arm; it moves a read/write head into position over a particular track. The read/write head on the end of the access arm hovers just above the track but does not actually touch the surface. When a read/write head does accidentally touch the disk surface, this is called a head crash and all data is destroyed. Data can also be destroyed if a read/write head encounters even minuscule foreign matter on the disk surface. A disk pack has a series of access arms that slip in between the disks in the pack. Two read/write heads are on each arm, one facing up for the surface above it and one facing down for the surface below it. However, only one read/write head can operate at any one time.

In some disk drives the access arms can be retracted; then the disk pack can be removed from the drive. Most disk packs, however, combine the disks, access arms, and read/write heads in a sealed module called a Winchester disk. Winchester disk assemblies are put together in clean rooms so even microscopic dust particles do not get on the disk surface.

Hard disks for personal computers are 5-1/4 inch or 3-1/2 inch disks in sealed modules and even gigabytes are not unusual. Hard disk capacity for personal computers has soared in recent years; capacities of hundreds of megabytes are common and gigabytes are not unusual. Although an individual probably cannot imagine generating enough output-letters, budgets, reports, and so forth-to fill a hard disk, software packages take up a lot of space and can make a dent rather quickly. Furthermore, graphics images and audio and video files require large file capacities. Perhaps more important than capacity, however, is the convenience of speed. Personal computer users find accessing files on a hard disk is significantly faster and thus more convenient than accessing files on a diskette.


Figure 2: Hard Disk and Drive

Removable Storage: Zip Disks


Figure 3: Iomega Zip Disk

Personal computer users, who never seem to have enough hard disk storage space, may turn to a removable hard disk cartridge. Once full, a removable hard disk cartridge can be replaced with a fresh one. In effect, a removable cartridge is as portable as a diskette, but the disk cartridge holds much more data. Removable units also are important to businesses concerned with security, because the units can be used during business hours but hidden away during off hours. A disadvantage of a removable hard disk is that it takes longer to access data than a built-in hard drive.

The most popular removable disk media is the Zip drive from Iomega (Figure 3). Over 100's of millions have been sold, making it the de facto standard. The disk cartridges look like a floppy disk, but are slightly bigger in all dimensions. Older Zip disks hold 100MB, newer ones hold 250MB and cost $8-$10 a piece (Floppies hold 1.4MB and cost around $2). The drive sells for around $80- $125. Many new PCs come with Zip drives built in addition to floppy drives. Zip disks are a great way to store large files and software programs.

Hard Disks in Groups
A concept of using several small disks that work together as a unit is called a redundant array of inexpensive disks, or simply RAID. The group of connected disks operates as if it were just one large disk, but it speeds up reading and writing by having multiple access paths. The data file for, say, aircraft factory tools, may be spread across several disks; thus, if the computer is used to look up tools for several workers, the computer need not read the data in turn but instead read them at the same time in parallel. Furthermore, data security is improved because if a disk fails, the disk system can reconstruct data on an extra disk; thus, computer operations can continue uninterrupted. This is significant data insurance.

How Data Is Organized on a Disk
There is more than one way of physically organizing data on a disk. The methods we will consider here are the sector method and the cylinder method.

The Sector Method
In the sector method each track is divided into sectors that hold a specific number of characters. Data on the track is accessed by referring to the surface number, track number, and sector number where the data is stored. The sector method is used for diskettes as well as disk packs.

Zone Recording
The fact that a disk is circular presents a problem: The distances around the tracks on the outside of the disk are greater than that of the tracks or the inside. A given amount of data that takes up 1 inch of a track on the inside of a disk might be spread over several inches on a track near the outside of a disk. This means that the tracks on the outside are not storing data as efficiently.

Zone recording involves dividing a disk into zones to take advantage of the storage available on all tracks, by assigning more sectors to tracks in outer zones than to those in inner zones. Since each sector on the disk holds the same amount of data, more sectors mean more data storage than if all tracks had the same number of sectors.

The Cylinder Method
A way to organize data on a disk pack is the cylinder method. The organization in this case is vertical. The purpose is to reduce the time it takes to move the access arms of a disk pack into position. Once the access arms are in position, they are in the same vertical position on all disk surfaces.

To appreciate this, suppose you had an empty disk pack on which you wished to record data. You might be tempted to record the data horizontally-to start with the first surface, fill track 000, then fill track 001, track 002, and so on, and then move to the second surface and again fill tracks 000, 001, 002, and so forth. Each new track and new surface, however, would require movement of the access arms, a relatively slow mechanical process.

Recording the data vertically, on the other hand, substantially reduces access arm movement. The data is recorded on the tracks that can be accessed by one positioning of the access arms-that is, on one cylinder. To visualize cylinder organization, pretend a cylindrically shaped item, such as a tin can, were figuratively dropped straight down through all the disks in the disk pack. All the tracks thus encountered, in the same position on each disk surface, comprise a cylinder. The cylinder method, then, means all tracks of a certain cylinder on a disk pack are lined up one beneath the other, and all the vertical tracks of one cylinder are accessible by the read/write heads with one positioning of the access arms mechanism. Tracks within a cylinder are numbered according to this vertical perspective: A 20-surface disk pack contains cylinder tracks numbered 0 through 19, top to bottom.

Optical Disk Storage
The explosive growth in storage needs has driven the computer industry to provide cheaper, more compact, and more versatile storage devices with greater capacity. This demanding shopping list is a description of the optical disk, like a CD. The technology works like this: A laser hits a layer of metallic material spread over the surface of a disk. When data is being entered, heat from the laser produces tiny spots on the disk surface. To read the data, the laser scans the disk, and a lens picks up different light reflections from the various spots.


Figure 3: Compact Disk (CD) and Drive)

Optical storage technology is categorized according to its read/write capability. Read-only media are recorded on by the manufacturer and can be read from but not written to by the user. Such a disk cannot, obviously, be used for your files, but manufacturers can use it to supply software. Applications software packages sometimes include a dozen diskettes or more; all these could fit on one optical disk with plenty of room to spare. The most prominent optical technology is the CD-ROM, for compact disk read-only memory. The disk in its drive is shown in Figure 3.
Figure 3: Compact Disk (CD) and Drive)
CD-ROM has a major advantage over other optical disk designs: The disk format is identical to that of audio compact disks, so the same dust-free manufacturing plants that are now stamping out digital versions of Mozart or Mary Chapin Carpenter can easily convert to producing anything from software to an encyclopedia. Furthermore, CD-ROM storage is large -up to 660 megabytes per disk, the equivalent of over 400 3-1/2 inch diskettes.

When buying a computer the speed of the CD-ROM drive is advertised using an "X" factor, like 12X, or 24X. This indicates the speed at which the CD can transfer data to the CPU - the higher the X factor, the faster the CD.

Modern computers now offer a write CD drive or, CD-RW as an option. CD-RW is a write-once, read-many media. With a CD-RW drive, you can create your own CDs. This offers an inexpensive, convenient, safe way to store large volumes of data such as favorite songs, photographs, etc.

DVDs
Digital Versatile Disk (DVD) drives are now widely available in computers as well as home entertainment centers. DVD-ROM drives can read data, such as stored commercial videos for playing. DVD-RW allow DVDs to be created on a computer.


Figure 4: DVD Disk and Drive

The DVD is a flat disk, the size of a CD - 4.7 inches diameter and .05 inches thick. Data are stored in a small indentation in a spiral track, just like in the CD. DVD disks are read by a laser beam of shorter wave-length than used by the CD ROM drives. This allows for smaller indentations and increased storage capacity. The data layer is only half as thick as in the CD-ROM. This opens the possibility to write data in two layers. The outer gold layer is semi transparent, to allow reading of the underlying silver layer. The laser beam is set to two different intensities, strongest for reading the underlying silver layer.

A 4.7 GB side of a DVD can hold 135 minutes top quality video with 6 track stereo. This requires a transmission rate of 4692 bits per second. The 17 GB disk holds 200 hours top quality music recording.

DVD movies are made in two "codes." Region one is USA and Canada, while Europe and Asia is region two. When you play movies, your hardware (MPEG decoder. MGEG is the data coding for movies similar to JPEG for pictures.) must match the DVD region. The movies are made in two formats, each with their own coding.

The DVD drives come in 2X, 4X, etc. versions, like the CD-ROM's.

The DVD drives will not replace the magnetic hard disks. The hard disks are being improved as rapidly as DVD, and they definitely offer the fastest seek time and transmission rate (currently 5-10 MB/second). No optic media can keep up with this. But the DVD will undoubtedly gain a place as the successor to the CD ROM and is playing an important role in the blending of computers and entertainment centers.

# Magnetic Tape Storage
We saved magnetic tape storage for last because it has taken a subordinate role in storage technology. Magnetic tape looks like the tape used in music cassettes plastic tape with a magnetic coating. As in other magnetic media, data is stored as extremely small magnetic spots. Tapes come in a number of forms, including l/2-inch-wide tape wound on a reel, l/4-inch- wide tape in data cartridges and cassettes, and tapes that look like ordinary music cassettes but are designed to store data instead of music. The amount of data on a tape is expressed in terms of density, which is the number of characters per inch (cpi) or bytes per inch (bpi) that can be stored on the tape.

The highest-capacity tape is the digital audio tape, or DAT, which uses a different method of recording data. Using a method called helical scan recording, DAT wraps around a rotating read/write head that spins vertically as it moves. This places the data in diagonal bands that run across the tape rather than down its length. This method produces high density and faster access to data.

Two reels are used, a supply reel and a take-up reel. The supply reel, which has the tape with data on it or on which data will be recorded, is the reel that is changed. The take-up reel always stays with the magnetic tape unit. Many cartridges and cassettes have the supply and take-up reels built into the same case.

Tape now has a limited role because disk has proved the superior storage medium. Disk data is quite reliable, especially within a sealed module. Furthermore, as we will see, disk data can be accessed directly, as opposed to data on tape, which can be accessed only by passing by all the data ahead of it on the tape. Consequently, the primary role of tape today is as an inexpensive backup medium.

# Backup Systems
Although a hard disk is an extremely reliable device, a hard disk drive is subject to electromechanical failures that cause loss of data. Furthermore, data files, particularly those accessed by several users, are subject to errors introduced by users. There is also the possibility of errors introduced by software. With any method of data storage, a backup system a way of storing data in more than one place to protect it from damage and errors is vital. As we have already noted, magnetic tape is used primarily for backup purposes. For personal computer users, an easy and inexpensive way to back up a hard disk file is to simply copy it to a diskette whenever it is updated. But this is not practical for a system with many files or many users.

Personal computer users have the option of purchasing their own tape backup system, to be used on a regular basis for copying all data from hard disk to a high-capacity tape. Data thus saved can be restored to the hard disk later if needed. A key advantage of a tape backup system is that it can copy the entire hard disk in minutes, saving you the trouble of swapping diskettes in and out of the machine.

posted by Marvstyles
11:16 PM
1 comments

Sunday, April 20, 2008

Figure 0 shows the parts of a computer:

* The Central Processing Unit:
o (CPU),
o Buses,
o Ports and controllers,
o ROM;
* Main Memory (RAM);
* Input Devices;
* Output Devices;
* Secondary Storage;
o floppy disks,
o hard disk,
o CD-ROM



Figure 0: Inside The Computer

This part of the reading will examine the CPU, Buses, Controllers, and Main Memory. Other sections will examine input devices, output devices, and secondary memory.
The Central Processing Unit (CPU).



Figure 1: The Central Processing Unit

The computer does its primary work in a part of the machine we cannot see, a control center that converts data input to information output. This control center, called the central processing unit (CPU), is a highly complex, extensive set of electronic circuitry that executes stored program instructions. All computers, large and small, must have a central processing unit. As Figure 1 shows, the central processing unit consists of two parts: The control unit and the arithmetic/logic unit. Each part has a specific function.
Before we discuss the control unit and the arithmetic/logic unit in detail, we need to consider data storage and its relationship to the central processing unit. Computers use two types of storage: Primary storage and secondary storage. The CPU interacts closely with primary storage, or main memory, referring to it for both instructions and data. For this reason this part of the reading will discuss memory in the context of the central processing unit. Technically, however, memory is not part of the CPU.

Recall that a computer's memory holds data only temporarily, at the time the computer is executing a program. Secondary storage holds permanent or semi-permanent data on some external magnetic or optical medium. The diskettes and CD-ROM disks that you have seen with personal computers are secondary storage devices, as are hard disks. Since the physical attributes of secondary storage devices determine the way data is organized on them, we will discuss secondary storage and data organization together in another part of our on-line readings.

Now let us consider the components of the central processing unit.

# The Control Unit
The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out, or execute, stored program instructions. Like an orchestra leader, the control unit does not execute program instructions; rather, it directs other parts of the system to do so. The control unit must communicate with both the arithmetic/logic unit and memory.

# The Arithmetic/Logic Unit
The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all arithmetic and logical operations.

The arithmetic/logic unit can perform four kinds of arithmetic operations, or mathematical calculations: addition, subtraction, multiplication, and division. As its name implies, the arithmetic/logic unit also performs logical operations. A logical operation is usually a comparison. The unit can compare numbers, letters, or special characters. The computer can then take action based on the result of the comparison. This is a very important capability. It is by comparing that a computer is able to tell, for instance, whether there are unfilled seats on airplanes, whether charge- card customers have exceeded their credit limits, and whether one candidate for Congress has more votes than another.

Logical operations can test for three conditions:

* Equal-to condition. In a test for this condition, the arithmetic/logic unit compares two values to determine if they are equal. For example: If the number of tickets sold equals the number of seats in the auditorium, then the concert is declared sold out.
* Less-than condition. To test for this condition, the computer compares values to determine if one is less than another. For example: If the number of speeding tickets on a driver's record is less than three, then insurance rates are $425; otherwise, the rates are $500.
* Greater-than condition. In this type of comparison, the computer determines if one value is greater than another. For example: If the hours a person worked this week are greater than 40, then multiply every extra hour by 1.5 times the usual hourly wage to compute overtime pay.
A computer can simultaneously test for more than one condition. In fact, a logic unit can usually discern six logical relationships: equal to, less than, greater than, less than or equal to, greater than or equal to, and not equal.

The symbols that let you define the type of comparison you want the computer to perform are called relational operators. The most common relational operators are the equal sign(=), the less-than symbol(<), and the greater-than symbol(>).

* Registers: Temporary Storage Areas
Registers are temporary storage areas for instructions or data. They are not a part of memory; rather they are special additional storage locations that offer the advantage of speed. Registers work under the direction of the control unit to accept, hold, and transfer instructions or data and perform arithmetic or logical comparisons at high speed. The control unit uses a data storage register the way a store owner uses a cash register-as a temporary, convenient place to store what is used in transactions.

Computers usually assign special roles to certain registers, including these registers:
o An accumulator, which collects the result of computations.
o An address register, which keeps track of where a given instruction or piece of data is stored in memory. Each storage location in memory is identified by an address, just as each house on a street has an address.
o A storage register, which temporarily holds data taken from or about to be sent to memory.
o A general-purpose register, which is used for several functions.

* Memory and Storage
Memory is also known as primary storage, primary memory, main storage, internal storage, main memory, and RAM (Random Access Memory); all these terms are used interchangeably by people in computer circles. Memory is the part of the computer that holds data and instructions for processing. Although closely associated with the central processing unit, memory is separate from it. Memory stores program instructions or data for only as long as the program they pertain to is in operation. Keeping these items in memory when the program is not running is not feasible for three reasons:
o Most types of memory only store items while the computer is turned on; data is destroyed when the machine is turned off.
o If more than one program is running at once (often the case on large computers and sometimes on small computers), a single program can not lay exclusive claim to memory.
o There may not be room in memory to hold the processed data.

How do data and instructions get from an input device into memory? The control unit sends them. Likewise, when the time is right, the control unit sends these items from memory to the arithmetic/logic unit, where an arithmetic operation or logical operation is performed. After being processed, the information is sent to memory, where it is hold until it is ready to he released to an output unit.

The chief characteristic of memory is that it allows very fast access to instructions and data, no matter where the items are within it. We will discuss the physical components of memory-memory chips-later in this chapter.

To see how registers, memory, and second storage all work together, let us use the analogy of making a salad. In our kitchen we have:
o a refrigerator where we store our vegetables for the salad;
o a counter where we place all of our veggies before putting them on the cutting board for chopping;
o a cutting board on the counter where we chop the vegetables;
o a recipe that details what veggies to chop;
o the corners of the cutting board are kept free for partially chopped piles of veggies that we intend to chop more or to mix with other partially chopped veggies.
o a bowl on the counter where we mix and store the salad;
o space in the refrigerator to put the mixed salad after it is made.
The process of making the salad is then: bring the veggies from the fridge to the counter top; place some veggies on the chopping board according to the recipe; chop the veggies, possibly storing some partially chopped veggies temporarily on the corners of the cutting board; place all the veggies in the bowl to either put back in the fridge or put directly on the dinner table.

The refrigerator is the equivalent of secondary (disk) storage. It can store high volumes of veggies for long periods of time. The counter top is the equivalent of the computer's motherboard - everything is done on the counter (inside the computer). The cutting board is the ALU - the work gets done there. The recipe is the control unit - it tells you what to do on the cutting board (ALU). Space on the counter top is the equivalent of RAM memory - all veggies must be brought from the fridge and placed on the counter top for fast access. Note that the counter top (RAM) is faster to access than the fridge (disk), but can not hold as much, and can not hold it for long periods of time. The corners of the cutting board where we temporarily store partially chopped veggies are equivalent to the registers. The corners of the cutting board are very fast to access for chopping, but can not hold much. The salad bowl is like a temporary register, it is for storing the salad waiting to take back to the fridge (putting data back on a disk) or for taking to the dinner table (outputting the data to an output device).

Now for a more technical example. let us look at how a payroll program uses all three types of storage. Suppose the program calculates the salary of an employee. The data representing the hours worked and the data for the rate of pay are ready in their respective registers. Other data related to the salary calculation-overtime hours, bonuses, deductions, and so forth-is waiting nearby in memory. The data for other employees is available in secondary storage. As the CPU finishes calculations about one employee, the data about the next employee is brought from secondary storage into memory and eventually into the registers.

Modern computers are designed with this hierarchy due to the characteristics listed in the table. It has been the cheapest way to get the functionality. However, as RAM becomes cheaper, faster, and even permanent, we may see disks disappear as an internal storage device. Removable disks, like Zip disks or CDs (we describe these in detail in the online reading on storage devices) will probably remain in use longer as a means to physically transfer large volumes of data into the computer. However, even this use of disks will probably be supplanted by the Internet as the major (and eventually only) way of transferring data. Floppy disks drives are already disappearing: the new IMac Macintosh from Apple does not come with one. Within the next five years most new computer designs will only include floppy drives as an extra for people with old floppy disks that they must use.

* How the CPU Executes Program Instructions
Let us examine the way the central processing unit, in association with memory, executes a computer program. We will be looking at how just one instruction in the program is executed. In fact, most computers today can execute only one instruction at a time, though they execute it very quickly. Many personal computers can execute instructions in less than one-millionth of a second, whereas those speed demons known as supercomputers can execute instructions in less than one-billionth of a second.



Figure 2: The Machine Cycle

Before an instruction can be executed, program instructions and data must be placed into memory from an input device or a secondary storage device (the process is further complicated by the fact that, as we noted earlier, the data will probably make a temporary stop in a register). As Figure 2 shows, once the necessary data and instruction are in memory, the central processing unit performs the following four steps for each instruction:

1. The control unit fetches (gets) the instruction from memory.
2. The control unit decodes the instruction (decides what it means) and directs that the necessary data be moved from memory to the arithmetic/logic unit. These first two steps together are called instruction time, or I-time.
3. The arithmetic/logic unit executes the arithmetic or logical instruction. That is, the ALU is given control and performs the actual operation on the data.
4. Thc arithmetic/logic unit stores the result of this operation in memory or in a register. Steps 3 and 4 together are called execution time, or E-time.
The control unit eventually directs memory to release the result to an output device or a secondary storage device. The combination of I-time and E-time is called the machine cycle. Figure 3 shows an instruction going through the machine cycle.

Each central processing unit has an internal clock that produces pulses at a fixed rate to synchronize all computer operations. A single machine-cycle instruction may be made up of a substantial number of sub-instructions, each of which must take at least one clock cycle. Each type of central processing unit is designed to understand a specific group of instructions called the instruction set. Just as there are many different languages that people understand, so each different type of CPU has an instruction set it understands. Therefore, one CPU-such as the one for a Compaq personal computer-cannot understand the instruction set from another CPU-say, for a Macintosh.



Figure 3: The Machine Cycle in Action

it is one thing to have instructions and data somewhere in memory and quite another for the control unit to be able to find them. How does it do this?



Figure 4: Memory Addresses Like Mailboxes

The location in memory for each instruction and each piece of data is identified by an address. That is, each location has an address number, like the mailboxes in front of an apartment house. And, like the mailboxes, the address numbers of the locations remain the same, but the contents (instructions and data) of the locations may change. That is, new instructions or new data may be placed in the locations when the old contents no longer need to be stored in memory. Unlike a mailbox, however, a memory location can hold only a fixed amount of data; an address can hold only a fixed number of bytes - often two bytes in a modern computer.

Figure 4 shows how a program manipulates data in memory. A payroll program, for example, may give instructions to put the rate of pay in location 3 and the number of hours worked in location 6. To compute the employee's salary, then, instructions tell the computer to multiply the data in location 3 by the data in location 6 and move the result to location 8. The choice of locations is arbitrary - any locations that are not already spoken for can be used. Programmers using programming languages, however, do not have to worry about the actual address numbers, because each data address is referred to by a name. The name is called a symbolic address. In this example, the symbolic address names are Rate, Hours, and Salary.

posted by Marvstyles
11:56 PM
0 comments

Many people upload cd images for games and tutorials. CD images are files such as ISO, CUE etc.

Download Daemon Tools

Install it using the installer. Once its installed, launch it, and now it will sit on the taskbar.

Now right click on the icon, go up to Virtual CD/DVD-ROM, and go across to the device and mount image.

Now select your CUE/ISO or whatever file you saved.

It should now autorun, but if you don't get an autorun, go to my computer and select the appropriate icon (daemon tools will create a virtual cd drive).

Explore the drive and you will then be presented with the contents of the cd.

If you want to eject the cd, right click go up to Virtual CD/DVD ROM then your device and across to unmount images.

Thats all for this tutorial, hope this helps all of you guys.

posted by Marvstyles
11:42 PM
0 comments

Wednesday, April 16, 2008

"Fatal error: the system has become unstable or is busy," it says. "Enter to return to Windows or press Control-Alt-Delete to restart your computer. If you do this you will lose any unsaved information in all open applications."

You have just been struck by the Blue Screen of Death. Anyone who uses Microsoft Windows will be familiar with this. What can you do? More importantly, how can you prevent it happening?


1. Hardware conflict

The number one reason why Windows crashes is hardware conflict. Each hardware device communicates to other devices through an interrupt request channel (IRQ). These are supposed to be unique for each device.

For example, a printer usually connects internally on IRQ 7. The keyboard usually uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a single IRQ for itself.

If there are a lot of devices, or if they are not installed properly, two of them may end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. The way to check if your computer has a hardware conflict is through the following route:

* Start-Settings-Control Panel-System-Device Manager.

Often if a device has a problem a yellow '!' appears next to its description in the Device Manager. Highlight Computer (in the Device Manager) and press Properties to see the IRQ numbers used by your computer. If the IRQ number appears twice, two devices may be using it.

Sometimes a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The best way to fix this problem is to remove the problem device and reinstall it.

Sometimes you may have to find more recent drivers on the internet to make the device function properly. A good resource is www.driverguide.com. If the device is a soundcard, or a modem, it can often be fixed by moving it to a different slot on the motherboard (be careful about opening your computer, as you may void the warranty).

When working inside a computer you should switch it off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity.

To be fair to Microsoft, the problem with IRQ numbers is not of its making. It is a legacy problem going back to the first PC designs using the IBM 8086 chip. Initially there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run out of them. There are plans to increase the number of IRQs in future designs.

2. Bad Ram

Ram (random-access memory) problems might bring on the blue screen of death with a message saying Fatal Exception Error. A fatal error indicates a serious hardware problem. Sometimes it may mean a part is damaged and will need replacing.

But a fatal error caused by Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond (70ns) Ram with 60ns Ram will usually force the computer to run all the Ram at the slower speed. This will often crash the machine if the Ram is overworked.

One way around this problem is to enter the BIOS settings and increase the wait state of the Ram. This can make it more stable. Another way to troubleshoot a suspected Ram problem is to rearrange the Ram chips on the motherboard, or take some of them out. Then try to repeat the circumstances that caused the crash. When handling Ram try not to touch the gold connections, as they can be easily damaged.

Parity error messages also refer to Ram. Modern Ram chips are either parity (ECC) or non parity (non-ECC). It is best not to mix the two types, as this can be a cause of trouble.

EMM386 error messages refer to memory problems but may not be connected to bad Ram. This may be due to free memory problems often linked to old Dos-based programmes.

3. BIOS settings

Every motherboard is supplied with a range of chipset settings that are decided in the factory. A common way to access these settings is to press the F2 or delete button during the first few seconds of a boot-up.

Once inside the BIOS, great care should be taken. It is a good idea to write down on a piece of paper all the settings that appear on the screen. That way, if you change something and the computer becomes more unstable, you will know what settings to revert to.

A common BIOS error concerns the CAS latency. This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of 3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.

Microsoft Windows is better at allocating IRQ numbers than any BIOS. If possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is switched to 'yes' to allow Windows to do this.).

4. Hard disk drives

After a few weeks, the information on a hard disk drive starts to become piecemeal or fragmented. It is a good idea to defragment the hard disk every week or so, to prevent the disk from causing a screen freeze. Go to

* Start-Programs-Accessories-System Tools-Disk Defragmenter

This will start the procedure. You will be unable to write data to the hard drive (to save it) while the disk is defragmenting, so it is a good idea to schedule the procedure for a period of inactivity using the Task Scheduler.

The Task Scheduler should be one of the small icons on the bottom right of the Windows opening page (the desktop).

Some lockups and screen freezes caused by hard disk problems can be solved by reducing the read-ahead optimisation. This can be adjusted by going to

* Start-Settings-Control Panel-System Icon-Performance-File System-Hard Disk.

Hard disks will slow down and crash if they are too full. Do some housekeeping on your hard drive every few months and free some space on it. Open the Windows folder on the C drive and find the Temporary Internet Files folder. Deleting the contents (not the folder) can free a lot of space.

Empty the Recycle Bin every week to free more space. Hard disk drives should be scanned every week for errors or bad sectors. Go to

* Start-Programs-Accessories-System Tools-ScanDisk

Otherwise assign the Task Scheduler to perform this operation at night when the computer is not in use.

5. Fatal OE exceptions and VXD errors

Fatal OE exception errors and VXD errors are often caused by video card problems.

These can often be resolved easily by reducing the resolution of the video display. Go to

* Start-Settings-Control Panel-Display-Settings

Here you should slide the screen area bar to the left. Take a look at the colour settings on the left of that window. For most desktops, high colour 16-bit depth is adequate.

If the screen freezes or you experience system lockups it might be due to the video card. Make sure it does not have a hardware conflict. Go to

* Start-Settings-Control Panel-System-Device Manager

Here, select the + beside Display Adapter. A line of text describing your video card should appear. Select it (make it blue) and press properties. Then select Resources and select each line in the window. Look for a message that says No Conflicts.

If you have video card hardware conflict, you will see it here. Be careful at this point and make a note of everything you do in case you make things worse.

The way to resolve a hardware conflict is to uncheck the Use Automatic Settings box and hit the Change Settings button. You are searching for a setting that will display a No Conflicts message.

Another useful way to resolve video problems is to go to

* Start-Settings-Control Panel-System-Performance-Graphics

Here you should move the Hardware Acceleration slider to the left. As ever, the most common cause of problems relating to graphics cards is old or faulty drivers (a driver is a small piece of software used by a computer to communicate with a device).

Look up your video card's manufacturer on the internet and search for the most recent drivers for it.

6. Viruses

Often the first sign of a virus infection is instability. Some viruses erase the boot sector of a hard drive, making it impossible to start. This is why it is a good idea to create a Windows start-up disk. Go to

* Start-Settings-Control Panel-Add/Remove Programs

Here, look for the Start Up Disk tab. Virus protection requires constant vigilance.

A virus scanner requires a list of virus signatures in order to be able to identify viruses. These signatures are stored in a DAT file. DAT files should be updated weekly from the website of your antivirus software manufacturer.

An excellent antivirus programme is Mc@fee VirusScan by Network Associates ( www.nai.com). Another is N0rt0n AntiVirus 2000, made by Symantec ( www.symantec.com).

7. Printers

The action of sending a document to print creates a bigger file, often called a postscript file.

Printers have only a small amount of memory, called a buffer. This can be easily overloaded. Printing a document also uses a considerable amount of CPU power. This will also slow down the computer's performance.

If the printer is trying to print unusual characters, these might not be recognised, and can crash the computer. Sometimes printers will not recover from a crash because of confusion in the buffer. A good way to clear the buffer is to unplug the printer for ten seconds. Booting up from a powerless state, also called a cold boot, will restore the printer's default settings and you may be able to carry on.

8. Software

A common cause of computer crash is faulty or badly-installed software. Often the problem can be cured by uninstalling the software and then reinstalling it. Use N0rt0n Uninstall or Uninstall Shield to remove an application from your system properly. This will also remove references to the programme in the System Registry and leaves the way clear for a completely fresh copy.

The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to clean up the System Registry and remove obsolete entries. It works on Windows 95, Windows 98, Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and Windows 2000.

Read the instructions and use it carefully so you don't do permanent damage to the Registry. If the Registry is damaged you will have to reinstall your operating system. Reg Cleaner can be obtained from www.jv16.org

Often a Windows problem can be resolved by entering Safe Mode. This can be done during start-up. When you see the message "Starting Windows" press F4. This should take you into Safe Mode.

Safe Mode loads a minimum of drivers. It allows you to find and fix problems that prevent Windows from loading properly.

Sometimes installing Windows is difficult because of unsuitable BIOS settings. If you keep getting SUWIN error messages (Windows setup) during the Windows installation, then try entering the BIOS and disabling the CPU internal cache. Try to disable the Level 2 (L2) cache if that doesn't work.

Remember to restore all the BIOS settings back to their former settings following installation.

9. Overheating

Central processing units (CPUs) are usually equipped with fans to keep them cool. If the fan fails or if the CPU gets old it may start to overheat and generate a particular kind of error called a kernel error. This is a common problem in chips that have been overclocked to operate at higher speeds than they are supposed to.

One remedy is to get a bigger better fan and install it on top of the CPU. Specialist cooling fans/heatsinks are available from www.computernerd.com or www.coolit.com

CPU problems can often be fixed by disabling the CPU internal cache in the BIOS. This will make the machine run more slowly, but it should also be more stable.

10. Power supply problems

With all the new construction going on around the country the steady supply of electricity has become disrupted. A power surge or spike can crash a computer as easily as a power cut.

If this has become a nuisance for you then consider buying a uninterrupted power supply (UPS). This will give you a clean power supply when there is electricity, and it will give you a few minutes to perform a controlled shutdown in case of a power cut.

It is a good investment if your data are critical, because a power cut will cause any unsaved data to be lost

posted by Marvstyles
11:02 PM
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