COMPUTER HARDWARE

COMPUTER HARDWARE AND NETWORKING

Monday, September 30, 2013

Google Glass

Google Glass {“GLΛSS"} is a wearable computer with an optical head-mounted display (OHMD) that is being developed by Google. Google Glass is an attempt to free data from desktop computers and portable devices like phones and tablets, and place it right in front of your eyes. Google Glass displays information in a smartphone-like hands-free format that can communicate with the Internet via natural language voice commands.
Essentially, Google Glass is a camera, display, touchpad, battery and microphone built into spectacle frames so that you can perch a display in your field of vision, film, take pictures, search and translate on the go
While the frames do not currently have lenses fitted to them, Google is considering partnerships with sunglass retailers such as Ray-Ban or Warby Parker, and may also open retail stores to allow customers to try on the device. The Explorer Edition cannot be used by people who wear prescription glasses, but Google has confirmed that Glass will eventually work with frames and lenses that match the wearer's prescription; the glasses will be modular and therefore possibly attachable to normal prescription glasses.
Glass is being developed by Google X, which has worked on other futuristic technologies such as driverless cars. The project was announced on Google+ by Project Glass lead Babak Parviz, an electrical engineer who has also worked on putting displays into contact lenses; Steve Lee, a product manager and "geolocation specialist"; and Sebastian Thrun, who developed Udacity as well as worked on the autonomous car project. Google has patented the design of Project Glass. Thad Starner, an augmented reality expert, is a technical lead/manager on the project.

What can Google Glass do?


As well as Google's own list of features, the early apps for Google Glass provide a neat glimpse into the potential of the headset.
As well as photos and film - which require no explanation - you can use the Google hangout software to video conference with your friends and show them what you're looking at.
We'll be able to use Google Maps to get directions, although with GPS absent from the spec list, we'll need to tether Glass to your phone. Google offers the MyGlass app. This pairs your headset with an Android phone. As well as sharing GPS data, this means messages can be received, viewed on the display, and answered using the microphone and Google's voice-to-text functionality.
Google has given its Glass project a big boost by snapping up voice specialists DNNresearch.
That functionality will also bring the ability to translate the words being spoken to you into your own language on the display. Obviously you'll need a WiFi connection or a hefty data plan if you're in another country, but it's certainly a neat trick if it works.
Third parties are also already developing some rather cool/scary apps for Google Glass - including one that allows you to identify your friends in a crowd, and another that allows you to dictate an email.

Vignettes

Share what you can do with Glass. Vignettes superimpose a screenshot of your Glass display over your picture, so people can see what you see on Glass and in the world. Take a picture using Glass' camera button and tap to make vignette. Whatever is on the display when you take the picture will appear in the vignette

Play videos through search

Use Google Search to find and play videos.

Sound Search

Long press the touchpad for a Google search and swipe forward to start a sound search. Glass will listen for a moment and identify the name and artist. Alternatively, you can start a sound search by voice command. Say "ok glass, google what song is this?" from the Home menu.

Transit cards

Ditch the car and spare your feet. Now you can get your nearby mass transit directions directly on Glass.

Reminder cards

Set a reminder through Google search on your mobile phone or tablet and get reminded on your Glass timeline.

Nearby attractions

Glass will notify you of nearby attractions, say the Golden Gate Bridge or the Statue of Liberty, if you happen to stumble into their neighborhood.

Nearby photo spots

Glass will update your timeline if you're you're away from home and near a scenic vista or other notable photo spot.

News results in search

Get the latest news through a Glass search. Do a Google search from Glass on a newsworthy topic, and you'll see a dedicated news card on the subject.


Set up a Google Apps account

Those with Google Apps can now turn on the Glass service through their Admin console and set up their Glass on their Google Apps account. Most Google Apps are supported and we'll continue testing and adding services as we go. To test with us, switch your account by factory resetting your Glass through the Device info card in Settings, then set up Glass through the MyGlass website or Android app while signed in to your Google apps account.

Glass searches in search history

Searches performed on Glass are now updated in your Google search history. If you'd rather keep a search anonymous, deleting it from the timeline will also delete it from your search history. Alternatively, you can turn it off entirely from the search history website.

Remote control

If you have the MyGlass app on Android, you may have noticed you can screencast your Glass display to your phone from the MyGlass menu. Now, while you screencast, you can control Glass through your phone. Try it out by swiping your phone screen to browse your timeline.

Google Glass Technical specifications

Fit

Adjustable nosepads and durable frame fits any face. Extra nosepads in two sizes.

Camera

Google Glass has the ability to take photos and record 720p HD video. While video is recording, the screen stays on.

Audio

Bone Conduction Transducer

Storage

12 GB of usable memory, synced with Google cloud storage. 16 GB Flash total.

Touchpad

A touchpad is located on the side of Google Glass, allowing users to control the device by swiping through a timeline-like interface displayed on the screen.

Battery

One full day of typical use. Some features, like video calls and video recording, are more battery intensive.

Charger

Included Micro USB cable and charger.

FAQ

1. Is Google Glass is indestructible?
No.
Glass is robust, stable and built to fit into your life. But you might break it if you don’t handle it with care. Protect your Glass by using the pouch or another carrying case that you trust to keep Glass safe, dry, and awesome.
2. Is Glass useful everywhere?
Like everything, there is a time and a place.
It might be harder to hear Glass or use voice input commands in noisy areas, and it might be harder to see the Glass screen in bright sunlight. Also, you may be in certain places like a doctor’s office where those around you don’t feel comfortable being photographed or captured on video. Always consider your surroundings - just like you would with a cell phone. Above all, be considerate.
3. Can I use Glass while driving or bicycling?
It depends on where you are and how you use it.
As you probably know, most states have passed laws limiting the use of mobile devices while driving any motor vehicle, and most states post those rules on their department of motor vehicles websites. Read up and follow the law! Above all, even when you’re following the law, don’t hurt yourself or others by failing to pay attention to the road. The same goes for bicycling: whether or not any laws limit your use of Glass, always be careful.










Friday, September 13, 2013

Power-on self-test


When power is turned on, POST (Power-On Self-Test) is the diagnostic testing sequence that a computer's basic input/output system (or "starting program") runs to determine if the computer keyboard,
random access memory, disk drives, and other hardware are working correctly.
If the necessary hardware is detected and found to be operating properly, the computer begins to boot. If the hardware is not detected or is found not to be operating properly, the BIOS issues an error message which may be text on the display screen and/or a series of coded beeps, depending on the nature of the problem.The pattern of beeps may be a variable numbers of short beeps or a mixture of long and short beeps, depending on what type of BIOS is installed.
The patterns of beeps contain messages about the nature of the problem detected. For example, if the keyboard is not detected, a particular pattern of beeps will inform you of that fact. An error found in the POST is usually fatal (that is, it causes current program to stop running) and will halt the boot process, since the hardware checked is absolutely essential for the computer's functions.


General internal workings

  • verify the integrity of the BIOS code itself
  • determine the reason POST is being executed
  • find, size, and verify system main memory
  • discover, initialize, and catalog all system buses and devices
  • pass control to other specialized BIOS-es (if and when required)
  • provide a user interface for systems configuration
  • identify, organize, and select which devices are available for booting
  • construct whatever system environment that is required by the target OS

Fundamental structure/Error reporting/Original IBM POST error codes

  • 1 short beep - Normal POST - system is OK
  • 2 short beeps - POST error - error code shown on screen
  • No beep - Power supply or system board problem
  • Continuous beep - Power supply, system board, or keyboard problem
  • Repeating short beeps - Power supply or system board problem or keyboard
  • 1 long, 1 short beep - System board problem
  • 1 long, 2 short beeps - Display adapter problem (MDA, CGA)
  • 1 long, 3 short beeps - Enhanced Graphics Adapter (EGA)
  • 3 long beeps - 3270 keyboard card

POST AMI BIOS beep codes

  • 1 - Memory refresh timer error
  • 2 - Parity error in base memory (first 64 KB block)
  • 3 - Base memory read/write test error
  • 4 - Mother board timer not operational
  • 5 - Processor error
  • 6 - 8042 Gate A20 test error (cannot switch to protected mode)
  • 7 - General exception error (processor exception interrupt error)
  • 8 - Display memory error (system video adapter)
  • 9 - AMI BIOS ROM checksum error
  • 10 - CMOS shutdown register read/write error
  • 11 - Cache memory test failed

POST beep codes on CompTIA A+ Hardware Core exam Beeps Meaning

  • Steady,short beeps Power supply may be bad
  • Long continuous beep tone Power supply bad or not plugged into correctly
  • Steady, long beeps Power supply bad
  • No beep Power supply bad, system not plugged in, or power not turned on
  • One long, two short beeps Video card failure

IBM POST diagnostic code descriptions

  • 100 to 199 - System boards
  • 200 to 299 - Memory
  • 300 to 399 - Keyboard
  • 400 to 499 - Monochrome display
  • 500 to 599 - Color/graphics display
  • 600 to 699 - Floppy-disk drive or adapter
  • 700 to 799 - Math coprocessor
  • 900 to 999 - Parallel printer port
  • 1000 to 1099 - Alternate printer adapter
  • 1100 to 1299 - Asynchronous communication device, adapter, or port
  • 1300 to 1399 - Game port
  • 1400 to 1499 - Color/graphics printer
  • 1500 to 1599 - Synchronous communication device, adapter, or port
  • 1700 to 1799 - Hard drive and/or adapter
  • 1800 to 1899 - Expansion unit (XT)
  • 2000 to 2199 - Bisynchronous communication adapter
  • 2400 to 2599 - EGA system-board video (MCA)
  • 3000 to 3199 - LAN adapter
  • 4800 to 4999 - Internal modem
  • 7000 to 7099 - Phoenix BIOS chips
  • 7300 to 7399 - 3.5-inch disk drive
  • 8900 to 8999 - MIDI adapter
  • 11200 to 11299 - SCSI adapter
  • 21000 to 21099 - SCSI fixed disk and controller
  •  21500 to 21599 - SCSI CD-ROM system

Macintosh POST

  • 1 beep = No RAM installed/detected
  • 2 beeps = Incompatible RAM type installed (for example, EDO)
  • 3 beeps = No RAM banks passed memory testing
  • 4 beeps = Bad checksum for the remainder of the boot ROM
  • 5 beeps = Bad checksum for the ROM boot block
  • 1 beep = no RAM installed
  • 2 beeps = incompatible RAM types
  • 3 beeps = no good banks
  • 4 beeps = no good boot images in the boot ROM (and/or bad sys config block)
  • 5 beeps = processor is not usable

On power up, the main duties of POST are handled by the BIOS, which may hand some of these duties to other programs designed to initialize very specific peripheral devices, notably for video and SCSI initialization. These other duty-specific programs are generally known collectively as option ROMs or individually as the video BIOS, SCSI BIOS, etc.

The principal duties of the main BIOS during POST are as follows:

The BIOS will begin its POST duties when the CPU is reset. The first memory location the CPU tries to execute is known as the reset vector. In the case of a hard reboot, the north-bridge will direct this code fetch (request) to the BIOS located on the system flash memory. For a warm boot, the BIOS will be located in the proper place in RAM and the north-bridge will direct the reset vector call to the RAM.
During the POST flow of a contemporary BIOS, one of the first things a BIOS should do is determine the reason it is executing. For a cold boot, for example, it may need to execute all of its functionality. If, however, the system supports power savings or quick boot methods, the BIOS may be able to circumvent the standard POST device discovery, and simply program the devices from a reloaded system device table.
The POST flow for the PC has developed from a very simple, straightforward process to one that is complex and convoluted. During POST, the BIOS must integrate a plethora of competing, evolving, and even mutually exclusive standards and initiatives for the matrix of hardware and OSes the PC is expected to support. However, the average user still knows the POST and BIOS only through its simple visible memory tests and setup screen.
In the case of the IBM PC compatible machines, the main BIOS is divided into two basic sections. The POST section, or POST code, is responsible for the tasks mentioned above, and the environment POST constructs for the OS is known as the run-time code, the run-time BIOS, or the run-time footprint. Primarily these two divisions can be distinguished in that POST code should be flushed from memory before control is passed to the target OS while the run-time code remains resident in memory. This division may be a misleading oversimplification, however, as many Run-time functions are executed while the system is Posting.
The original IBM BIOS reported errors detected during POST by outputting a number to a fixed I/O port address, 80. Using a logic analyzer or a dedicated POST card, an interface card that shows port 80 output on a small display, a technician could determine the origin of the problem. (Note that once an operating system is running on the computer, the code displayed by such a board is often meaningless, since some OSes, e.g. Linux, use port 80 for I/O timing operations.) In later years, BIOS vendors used a sequence of beeps from the motherboard-attached loudspeaker to signal error codes.
These POST beep codes are covered specifically on the CompTIA A+ Core Hardware Exam:
Apple's Macintosh computers also perform a POST after a cold boot. In the event of a fatal error, the Mac will not make its start-up chime.
Old World Macs (until 1998)
Macs made prior to 1998, upon failing the POST, will immediately halt with a "death chime," which is a sound that varies by model; it can be a beep, a car crash sound, the sound of shattering glass, a short musical tone, or more. On the screen will be the Sad Mac icon, along with two hexadecimal strings, which can be used to identify the problem.
New World Macs (1998-1999)
When Apple introduced the iMac in 1998, it was a radical departure from other Macs of the time. The iMac began the production of New World Macs, as they are called; New World Macs, such as the iMac, Power Macintosh G3 (Blue & White), Power Mac G4 (PCI Graphics), PowerBook G3 (bronze keyboard), and PowerBook G3 (FireWire), load the Mac OS ROM from the hard drive. In the event of a fatal error, they give these beeps:
New World Macs (1999 onward) and Intel-based Macs
The beep codes were revised in October 1999, and have been the same since. In addition, on some models, the power LED would flash in cadence.

Thursday, September 12, 2013

Turn Your Laptop Into a Wifi Hotspot (WINDOWS XP / WINDOWS 7 / WINDOWS 8)Wifi Router

Turn Your WINDOWS 7/WINDOWS 8 Laptop Into a Wifi Hotspot (WIRELESS ROUTER)
Share your USB Modem/USB Internet Dongle to other devices using laptop or wireless PC
Connectify Hotspot is an easy-to-use software access point ( Soft AP ) or vritual router,  for laptops and smartphones. With Connectify Hotspot you can share expensive airport Wi-Fi with co-workers, create a wireless hotspot in your ethernet-only hotel or dorm room, and even extend the range of your home router. Other Wi-Fi-enabled devices can see and join your Connectify hotspot just like any other Wi-Fi access point, and are kept safe and secure by password-protected WPA2 Encryption.
Step by Step Procedure:-
Connectify presents you with a very easy-to-use wizard. Click “Next”, and select the Wi-Fi device you want
to use to share your Internet connection. If you only have one adapter, this screen doesn’t show up, so jump to step three!

Note: Some adapters might not allow both connecting to a Wi-Fi network (at home, work, or in public) and sharing the Internet connection at the same time. If that’s the case, you need a secondary Wi-Fi USB adapter.

3.Hit “Next”, and enter the name of the Wi-Fi hotspot that you want to create. Below is an example.

4. Then, select the “Hotspot Mode”. If your Wi-Fi connection is capable of sharing the same Wi-Fi for both the Internet connection and the Connectify hotspot feature, make sure that “Access Point, WPA2-PSK” is selected. If you want to set another security level (for compatibility reasons), then the Internet connection needs to come in from another source like a 3G card, a cable modem or a direct LAN connection.


5. Enter a password to protect your personal Wi-Fi hotspot, and hit “Next” again. The following step of the wizard is crucial; Connectify will now ask you which Internet connection you want to share. For example, let’s use the same Wi-Fi adapter.

6. That’s it! Click “Finish”, and in a few short moments, you will be able to connect all of your Wi-Fi-enabled devices to your laptop’s own hotspot.




Turn Your WINDOWS XP Laptop Into a Wifi Hotspot
First things first, set up the computer that’s connected to the modem to be the HOST. All this means is that this is the computer that will be used to share the internet, not the computer that doesn’t have internet currently. To do this, go:


WINDOWS XP

1. Start > Control Panel > Network Connections.

This should show all the connections you are or have been connected to.

DO THE STEP BY STEP PROCEDURE

Step 1: Right-Click the connection you are currently using to access the internet. Click Properties. Go to the Advanced tab and check “Allow other network users to connect through this computer’s Internet connection”.

Step 2: Click the drop down menu and select “Wireless Network Connection“. Click OK.

Step 3: Go back to Network Connections, right click Wireless Network Connection and select Properties. Click on the Wireless Networks tab.

Step 4: Click on the Advanced button, and select Computer-To-Computer (Ad-Hoc) Networks Only. Also, make sure that Automatically Connect To Non-Preferred Networks is unchecked. Close box.

Step 5: Click on the Add button, enter all the information required. Make sure Network Encryption is disabled.


Step 6: Right click the Wireless Connections icon in the bottom-right toolbar, and connect to the Wireless Connection you just created.


You've now successfully made your computer/laptop into a HOST computer in window xp operating system, and it will now act as a router for other computers/laptops to connect.



DOWNLOAD

Wednesday, September 11, 2013

Windows 7 USB/DVD tool


The Windows USB/DVD Download tool allows you to create a copy of your Windows 7 ISO file on a USB flash drive or a DVD.

To create a bootable DVD or USB flash drive, download the ISO file and then run the Windows 7 USB/DVD Download tool. Once this is done, you can install Windows 7 directly from the USB flash drive or DVD.

The ISO file contains all the Windows 7 installation files combined into a single uncompressed file. When you download the ISO file, you need to copy it to some medium in order to install Windows 7. This tool allows you to create a copy of the ISO file to a USB flash drive or a DVD. To install Windows 7 from your USB flash drive or DVD, all you need to do is insert the USB flash drive into your USB port or insert your DVD into your DVD drive and run Setup.exe from the root folder on the drive.
Pros
  • Very easy to use
  • No tech skills required
  • Creates a self-executable DVD or USB pen drive
Cons
  • No customization allowed
Installation
  • When you are prompted to either save the file to disk or run it, choose Run.
  • Follow the steps in the setup dialogs. You'll have the option to specify where to install the Windows 7 USB/DVD Download Tool.
NOTE: You need to be an administrator on the computer you are installing the Windows 7 USB/DVD Download tool on. The tool requires the Microsoft .NET Framework version 2.0 or higher.

System requirements
  • Windows XP SP2, Windows Vista, or Windows 7 (32-bit or 64-bit)
  • Pentium 233-megahertz (MHz) processor or faster (300 MHz is recommended)
  • 50MB of free space on your hard drive
  • DVD-R drive or 4GB removable USB flash drive
  • For Windows XP users
The following applications must be installed prior to installing the tool:

  • Microsoft .NET Framework 2.0 must be installed.
  • Microsoft Image Mastering API v2 must be installed.

Using the Windows 7 USB/DVD download tool

Before you run the Windows 7 USB/DVD Download Tool, make sure you have already purchased the Windows 7 ISO download from Microsoft Store and have downloaded the Windows 7 ISO file to your hard drive. If you have purchased Windows 7 but have not yet downloaded the ISO file, you can download the file from your Microsoft Store Account.

To make a copy of your Windows 7 ISO file:
  • Click the Windows START button, and click WINDOWS 7 USB/DVD DOWNLOAD TOOL in the ALL PROGRAMS list to open the Windows 7 USB/DVD Download Tool.
  • In the SOURCE FILE box, type the name and path of your Windows 7 ISO file, or click BROWSE and select the file from the OPEN dialog box. Click NEXT.
  • Select USB DEVICE to create a copy on a USB flash drive or select DVD disk to create a copy on a DVD disk.
  • If you are copying the file to a USB flash drive, select your USB device in the drop-down list and click BEGIN COPYING. If you are copying the file up to a DVD, click BEGIN BURNING.
  • When your Windows 7 ISO file is copied onto your chosen media, install Windows 7 by moving to the root folder of your DVD or USB flash drive, and then double-click Setup.exe.

Troubleshooting

The following tips might help if you run into a problem using this tool.
  • The tool is requested that I install the .NET framework and Image Mastering API before I install the tool
  1. For users running Windows XP, you must install the .NET Framework 2.0 and the Image Mastering API 2.0 before installing the tool. You can download .NET framework here and you can download the Image Mastering API here.
  2. Please note that a restart may be required after installing the .NET framework and the Image Mastering API.
  • When creating a bootable USB device, I am getting an error about bootsect
  1. To make the USB device bootable, you need to run a tool named bootsect.exe. In some cases, this tool needs to be downloaded from your Microsoft Store account. This may happen if you're trying to create a 64-bit bootable USB device from a 32-bit version of Windows. To download bootsect:
  2. Login to your Microsoft Store account to view your purchase history
  3. Look for your Windows 7 purchase.
  4. Next to Windows 7, there is an "Additional download options" drop-down menu.
  5. In the drop-down menu, select "32-bit ISO."
  6. Right-click the link, and then save the bootsect.exe file to the location where you installed the Windows 7 USB/DVD Download Tool (e.g. C:\Users\username\AppData\Local\Apps\Windows 7 USB DVD Download Tool).
  7. Once the file has been saved, go back to the Windows 7 USB/DVD Download tool to create your bootable USB device.
  • My USB device is not in the list of available devices
  1. If you don't see your USB flash drive in the list of available devices, please make sure the drive is inserted in the USB port, and then click the Refresh button beside the list of available drives.
  • I inserted a blank DVD in my DVD-ROM drive, but the Windows 7 USB/DVD Download Tool doesn't recognize it
  1. If there are multiple drives on the system, the tool will select the first one that is capable of burning DVDs. If you have multiple DVD-R drives, try inserting the blank DVD into another DVD-R drive. If that doesn't help, please make sure that your disc isn't damaged and that your DVD-R drive is operational. Contact Product Support if issues continue to arise.
  • Inserted a blank DVD in my DVD-ROM drive, but the tool won't let me burn it
  1. Make sure the disc isn't a dual-layer DVD disc. Currently, dual-layer discs are not supported within the tool.


Wednesday, January 16, 2013

Solid State Hard Disk


Solid state storage (SSS) is a method of data storage accomplished by using 
Solid State Hard Disk
Solid State Hard Disk
integrated circuit devices to store data rather than moving magnetic or optical media. SSS is typically non-volatile and may take various forms, such as a solid state drive, solid state card or solid state module. In addition, SSS includes PATA (legacy), SATA, SAS, Fibre Channel or PCIe interface options.Solid state drives (SSD) used in the enterprise are data storage devices that use non-moving flash memory technology rather than rotating magnetic disks or optical media. SSDs are compatible with traditional hard drive interfaces, such as SATA or SAS, and have a familiar hard drive form factor, such as 3.5-, 2.5- or 1.8-inch.Both USB flash drives and SSDs use NAND flash memory. However, it’s the quality of NAND used—as well as the controller and interface involved—that separates a simple USB flash drive from an enterprise-class storage device, like those found in blade servers and external storage systems.
Today’s SSDs are different from hard drives when it comes to data storage.SSDs are sophisticated storage devices that use non-moving memory chips, mostly non-volatile NAND flash, instead of the rotating magnetic disks found in hard drives. Hard drives can take the data directly from the host and write it to the rotating media. In contrast, SSDs can’t write a single bit of information without first erasing and then rewriting very large blocks of data at one time (also referred to as P/E).Because SSDs and hard drives have different strengths in terms of efficiency, they complement each other and can co-exist. SSDs deliver ultra-fast random data access (inputs-outputs per second, or IOPS, performance), low power consumption, small size and high physical resilience (due to no moving parts)—but they cost more. Hard drives provide fast sequential data access with high capacity, endurance and reliability at a much lower price. 
A process known as Wear-leveling is used by an SSD controller to maximize the life of the flash memory. This technique levels the wear across all blocks by distributing data writes across the flash memory devices.  
Solid state hard drives (SSDs) store data through the use of semi-conductors. Though they can cost substantially more than your traditional magnetic hard drive, they offer a few advantages:
Lower Power Consumption - SSDs consume less power because they have no moving parts. This attribute makes them less susceptible to physical shock and latency.
Faster Data Access - In normal situations, data is written and read from random locations on the disk. The lack of moving parts in SSDs cuts down on random read and write latency functions.
Increased Reliability - While the point can be argued, the lack of moving components makes SSDs less susceptible to head crash. They store, read and write information slightly differently than magnetic hard drives. For this reason, they are less susceptible to the problems magnetic hardware experience.
SOLID STATE HARD DISK DRIVE (SSD)
What are the challenges facing SSD?
There are three primary concerns impacting SSD adoption in the enterprise: 
Endurance and reliability, a lack of industry standards, and high cost.  
Endurance/Reliability Concerns 
SSDs wear out over time. NAND flash memory can only be written a certain 
number of times to each block (or cell). SLC memory generally sustains 50,000 program/erase (P/E) cycles, while MLC memory is generally ten times less at 5000 cycles. Once a block (or cell) is written to its limit, the block starts to forget what is stored and data corruption can occur. Seagate is actively developing techniques such as wear leveling algorithms to address endurance and reliability concerns.
Lack of Standards
SSDs store data differently than hard drives; therefore the time-tested and fieldproven industry standards used by hard drives do not equally apply when working with NAND flash technology. Seagate is actively leading SSS industry standards development through organizations such as JEDEC and SNIA to advance SSD adoption in the enterprise. 
High Cost
To date, the cost of SLC memory is roughly three times higher than MLC memory due to two factors.  First, MLC NAND stores two bits of data per cell and can provide twice the storage per square millimeter of silicon (the main cost of the memory). Second, the volume of MLC is roughly 90 percent of all NAND flash, further increasing the economies of scale in its production.Today, manufacturing facilities (fabs) are primarily focused on building MLC memory. Significant investment is needed to re-calibrate or build fabs that are designed to meet the quality, consistency and support levels required in the enterprise. Fabs are expensive and sophisticated operations.
Solid State Hard Drive Development

Solid state hard drives were first developed over 40 years ago; however, until recently SSDs were prohibitively expensive for the average consumer, making it impossible for computer manufacturers to include SSDs in their products. The surge in mobile computing devices has created a demand for solid state hard drives, leading tech companies to focus on developing low-cost, high-quality flash-based memory devices.  As a result, solid state hard drives are now affordable and readily available,  making  them a good alternative to traditional hard disk drives (HDDs).Most solid  state hard  drives use high-density NAND type flash memory,  the same type of memory  that is common in SD data cards and portable USB drives. The first mass-produced computer to use a solid state hard drive was the MacBook Air, an ultra-portable laptop introduced by Apple in 2008. Since then other manufacturers have begun including SSDs in their products, allowing them to build faster, lighter machines that are mobile-friendly. Consumers can now choose from a wide variety of replacement solid state hard drives that can be used to upgrade an existing hard drive or for use as an external data storage device.
How To Choose a Solid State Hard Drive
To upgrade your existing mechanical hard drive to a solid state drive, check both the dimensions and connectivity of your system. Most computers use a standard SATA cable hard drive interface, however, some require an ATA drive cable (also known as IDE or PATA). 2.5" is the most common solid state hard drive measurement, while some systems use either a 1.8" or a 3.5" drive. Adapters are readily available that allow 2.5" drives to be mounted in a standard desktop 3.5" hard drive bay. Once you know the size and interface type you need, consider how much actual data storage space you need on your hard drive. Thanks to the emergence of cloud-based computing and external drives, onboard hard drive capacities have been shrinking. At the bare minimum, choose a SSD that can comfortably accommodate your operating system along with some other software. For most users, a 60GB hard drive is the absolute minimum, while a 120GB drive will allow some room for data and additional programs.

Comparison of SSDs with memory cards
While both memory cards and most SSDs use flash memory, they serve very different markets and purposes. Each has a number of different attributes which are optimized and adjusted to best meet the needs of particular users. Some of these characteristics include power consumption, performance, size, and reliability.
SSDs were originally designed for use in a computer system. The first units were intended to replace or augment hard disk drives, so the operating system recognized them as a hard drive. Originally, solid state drives were even shaped and mounted in the computer like hard drives. Later SSDs became smaller and more compact, eventually developing their own unique form factors. The SSD was designed to be installed permanently inside a computer.
In contrast, memory cards (such as Secure Digital (SD), CompactFlash (CF) and many others) were originally designed for digital cameras and later found their way into cell phones, gaming devices, GPS units, etc. Most memory cards are physically smaller than SSDs, and designed to be inserted and removed repeatedly.There are adapters which enable some memory cards to interface to a computer, allowing use as an SSD, but they are not intended to be the primary storage device in the computer. The typical CompactFlash card interface is three to four times slower than an SSD. As memory cards are not designed to tolerate the amount of reading and writing which occurs during typical computer use, their data may get damaged unless special procedures are taken to reduce the wear on the card to a minimum.
Data recovery and secure deletion
Solid state drives have set new challenges for data recovery companies, as the way of storing data is much more non-linear and complex than that of hard disk drives.The strategy the drive operates by internally can largely vary between manufacturers and, the TRIM command zeroes the whole range of a deleted file. Wear leveling also means that the physical address of the data and the address exposed to the operating system are different.
As for secure deletion of data, using the ATA Secure Erase command is recommended, as the drive itself knows the most effective method to truly reset its data. A program such as Parted Magic can be used for this purpose.

Advantages and Disadvantages of Solid State Drive vs Hard Drive
Within the past several years, Solid State Disk Drives have become a popular alternative to the standard hard drive. They are completely silent, less prone to mechanical malfunction and are able to write and rewrite data at more than 50 times the speed of the standard hard drive.
For those considering a switch from a standard hard drive to an SSD, there are several advantages and disadvantages for you to consider:
Advantages to Using a Solid State Hard Disk
The speed of an SSD is not constrained by its parts, because there are no moving parts to a Solid State Drive.
Only a series of wires that moves at the speed of electricity.
Many SSD require lower power and produce less heat, resulting in a decrease in  electrical usage and a longer lifespan, especially in laptops that are prone to  overheating.
Because there is no disk to spin, a Solid State Disk Drive can start up over 25 times faster than the standard hard drive.
There is no noise, except in the case of the higher capacity storage spaces that tend to have cooling fans attached.
Both flash and DRAM Solid State Drives run at faster speeds than hard drives and continue to run at those speeds regardless of the amount of data being accessed.
Any physical occurrences, such as vibration, high movements or temperature fluctuations, do not affect SSDs to the same degree because there are no moving parts to break.
Disadvantages to Using a Solid State Hard Disk
The Solid State Disk price per gigabyte is much higher than hard drives, so an upgrade to the same GB capacity can incur some considerable costs.
While they are able to withstand movement, they are vulnerable to power loss and electrical/magnetic currents much in the same way as flash cards.
Currently there are very few large capacity SSD models, though this is expected to change drastically over the course of the next few years.
Flash SSD have limited write cycles. It is estimated that these write cycles will last until long after the computer is still being used, it is possible that some files could use write cycles often enough that it affects the owner/user.
Despite requiring less power, many SSD still use more power than the standard hard drive, especially when idle. This can cause laptop batteries to use up more quickly.
Solid State Drives have a variety of benefits, especially for businesses and those that use their laptops regularly. Still, SSD are not for everyone, and some people may still prefer to use the standard hard drive until the capacity, power usage and write cycle lifespan has increase on the available Solid State Hard Disks. It is estimated, however, that these changes will occur sooner rather than later.