Open source software security

Madirish Tutorial 03

30 November -0001
If you want to become an accomplished hacker you have to understand the insides of a computer. Now, this is probably really daunting for most folks, but its really not that scary. If you've never opened the case of you computer you should take this opportunity to do so. Make sure you unplug the power. Once that's done, unless you spill a beer on your motherboard there really isn't much harm you can do to your machine. Lets examine the basic parts of a computer.

The Motherboard
This is probably the most important part of a computer. The motherboard is the large plastic board that rests against the side of your computer's case. The motherboard houses the computer's processor chip and many other components. Some motherboards have what are called 'on-board' components. This means that other parts of your computer are built into the motherboard and can't be detached. I would recommend against purchasing computers with 'on-board' components because they can't be removed or replaced/upgraded. It is common to put video cards, Ethernet adaptors and even sound cards onto a motherboard. A good motherboard only has the processor embedded and the other components attached via expansion slots. The expansion slots are raised plastic housings that serve to hold card perpendicular to the board facing the outside of the case (usually the back). The motherboard is the most key component of any computer. Make sure that motherboards you wish to purchase have ample room for expansion slots, either PCI or other. PCI slots are short, usually about 5 inches in length, although traditional expansion slots are longer (usually about 7 inches long). Motherboards are the skeleton of your system, upon which you will connect all your other components.

The Hard Drive
The hard drive is usually a slim metal rectangular casing usually about the size of a CD jewel case but thicker. Hard drives consist of round magnetized plates that are stacked and spin inside the casing. Hard drives are the system's default storage system. The operating system and other programs can be loaded onto the hard drive. Hard drives vary in size. Today its possible to get hard drives with huge (40 gig or more) capacities. I used to feel lucky to have a 2 gig hard drive, and never really used up the space, but as operating systems and essential programs become larger you'll need bigger hard drives. Hard drives are connected to the motherboard via a thick gray cable with a long plastic end. Hard drives are replaceable, but keep in mind if you remove a hard drive you will remove all programs 'on the computer' including drivers and operating systems. It is possible to have more than one hard drive in a computer, but your operating system must support this configuration and its usually a real pain to get two working hard drives in most desktop computers.

The CD Drive
CD-ROM (Compact Disk Read Only Memory) drives are common these days. Speeds are measured in x, for instance 40x or 8x. Pretty much everything over 10x will do just fine for most computers. 40x is standard these days, but you really won't notice much effect due to the speed of your cd rom unless you are running a program directly off the CD (which is unusual these days, most computers load essential programs onto the hard drive and use the CD for peripheral functions such as sound tracks). DVD rom's are also becoming common. These can read the extended DVD (Digital Video Disk) format. DVD hasn't really caught on as a software medium, so unless you plan to use your computer to watch DVD movies I'd recommend a CD-RW instead of a DVD Rom. CD-RW (Compact Disk Read Write) drives can be used to "burn" new software of music CD's. CD's are coming to replace floppy disks as software storage mediums so I would recommend getting a CD-RW if you can afford it. The CD rom is usually held in the case inside its own housing sleeve by 4 bolts. The back of the CD drive is usually connected to the motherboard by one fat, wide plastic cable and to the power supply by a few wires, both with plastic ends.

The Floppy Drive
Floppy drives look like small CD drives on the inside of computers. Floppy drives are pretty standard and I would recommend having one even though the media is going out of style. New methods of storage on floppy disk are emerging and may spell a comeback for floppies. The major advantage to having a floppy drive is that most computers default boot off of floppy's before they boot off of their Hard Drive. This means that if your operating system becomes damaged, you may still be able to boot off of a boot disk if you have a floppy drive. Boot disks can also be used to subvert operating system security or to install a new operating system.

The Sound Card
Sound Cards are responsible for passing electronic signals to your speakers. Most sound cards are pretty standard and often are 'on-board' in newer computers. I would recommend Sound Blaster sound cards as they are the industry standard. You can often find your sound card attached via an expansion slot to your motherboard. You can spot it by the 'mic' and 'speaker' ports on its back. Unless you are a sound fanatic pretty much any sound card will do. To get the best sound invest in good speakers over a top of the line sound card. Just make sure your card is either a Sound Blaster or Sound Blaster fully compatible otherwise some sound may not work from certain programs.

The Video Card
Your video card translates digital signal to your monitor. Video cards are usually on board and pretty much all of them are industry standard. Today's newer computers usually also require a 3d graphics accelerator, which is basically an extra video card with processors to enhance video display. Video capabilities are measured in bits. I would recommend at least a 16 bit graphics card or accelerator, 64 bit for people that want to be able to play high end games. Video cards all have ports on them that allow you to plug standard monitors into them.

The Modem
Modems are modified phones. Their speed is measured in K. The fastest modem available currently is 56k, which is even faster than most analogue phone lines can handle. Other common speeds are 24.4k and 28.8k. This refers to the amount of kilobits your modem can upload/download per second. Even if you have a fast modem don't expect that all your downloads will operate at maximum speed since both the client and the host modems are a factor. Modems come in internal and external models. External modems usually plug into COM port expansion slots that are found on the motherboard. External modems are a bit more reliable as many internal modems tend to be Win-modems, or software modems. A software modem is a modem that stores much of its operating instructions in software wired onto the modem card. Such modems are notoriously difficult to configure with Linux.

Ethernet Cards
Ethernet cards are usually 10 base T cards that have an RJ-45 slot in their backs. Ethernet is used to communicate to LAN's and other computers. Many DSL modems require Ethernet cards to function since they communicate to computers through Ethernet. Ethernet cards come in many shapes and sizes. If you're going to get an Ethernet card I would recommend going with an industry standard. Netgear and 3-Com both make excellent Ethernet cards that will work with almost any computer. If you're going to get a new Ethernet card don't skimp on the money, you usually get what you pay for and spending an extra $10 could save you countless headaches in the future.

You may have heard drivers mentioned a lot, especially if you are installing a new operating system. What a driver is specifically, is a piece of software that tells your operating system how to send, receive, and interpret signals from a specific piece of hardware. As you can guess, this software is very important for the correct operation of you hardware. Using the wrong drivers could force your computer to function improperly, even damage your hardware. Be sure to use the latest device drivers provided by your manufacturer. If you're having a problem with one of your hardware devices, also make sure the driver is working properly. On a windows computer you can check your hardware configuration and driver status under Control Panel -> System -> Hardware Configuration -> Properties.