|
Computers
-
WHAT IS A "U" or more specifically a "RACK UNIT"?
-
What is an SSD (Solid State Drive)?
- Why do little PCs cost more than a commercial grade
home or office type PC?
- What Kind of applications would little PCs be used in?
- What is an embedded PC?
- What is Linux?
- What is Hyper-Threading
Technology From INTEL?
- The SBC (Single Board Computer) vs.
motherboards
- What is a watchdog timer?
- RIP - Death of The Floppy disc drive
Back to the FAQ Main Page
WHAT IS A "U" or more specifically a "RACK UNIT"?
As in 1U, 2U, 4U ... etc
A "Rack Unit" or "U" is an Electronic Industries Alliance or more commonly "EIA"
standard measuring unit for rack mount type equipment. This term has become more
prevalent in recent times due to the proliferation of rack mount products
showing up in a wide range of commercial, industrial and military markets. A
"Rack Unit" is equal to 1.75" in height. To calculate the internal useable space
of a rack enclosure you would simply multiply the total amount of Rack Units by
1.75". For example, a 44U rack enclosure would have 77" of internal usable space
(44 x 1.75).
Stealth manufactures computers and peripherals that are designed to fit into a
standard EIA size rack enclosures. Stealth's Rackmount PCs,
LCD Monitors and
Keyboards are available in many sizes and configurations. The slim space saving
series rack products are available in 1U (1.75") and 2U (3.5") in overall
height. Since rack space is at a premium these slim products represent
significant cost savings to the end user. Standard rackmount products are
available in 1U, 2U, 4U, 5U and 6U configurations.
What is an
SSD (Solid State Drive)
 SSD
is the acronym for Solid State Drive. SSD's are highly reliable
solid-state devices that replicate a standard IDE, SATA or SCSI
hard Disk Drive. They are available in standard form factors of,
1.8-inch, 2.5-inch, and 3.5-inch. An SSD using SRAM or DRAM
(instead of flash memory) is often called a RAM-drive.
Since they have no moving parts they can withstand extreme
shock, vibration, temperature, altitude and harsh environmental
conditions while operating without compromising on data
integrity. Standard models operate in temperatures of 0 - 70° C.
and special industrial models can withstand operating
temperatures of -40 - 85° C.
Due to its unique design, solid state drives eliminate seek
time, latency and other electro-mechanical delays inherent in
conventional disk drives, providing very fast access times. They
are the same size and shape as traditional desktop hard drives
and utilize the same connectors making them easy to install in
traditional PC based equipment.
What are the benefits of using a Flash Disk Drive?
- Extreme vibration & shock
- Extended temperature range
- Resistant to magnetic fields
- Low power requirements
- Fast access times
- Faster start up as there is no spin-up required
- Highly reliably
SSD's are ideal for industrial control, mobile computers, embedded
systems, test equipment or mission critical applications. Stealth.com
offers a wide range of solid state drives with their products.
Why do little PCs cost more than a commercial grade
home or office type PC?
Many of the LittlePC products are designed with
Industrial Single Board Computers (SBC), which offer
more functionality higher reliability, lower power and
smaller form factors. These embedded type boards are
not mass-produced as compared to commercial type
products therefore the economies of scale result in a
more costly product to produce.
What Kind of applications would little
PCs be used
in?
LittlePC products have
been used in a wide range of applications where size,
flexibility and special features are required. As
processor power continues to advance new applications
are developed where traditional PCs could not fit
into in the past. Some of the markets that use
littlePC type applications today are, Plant Floor- MMI,
Machine Control, Data Acquisition, Security, Internet
Servers, Thin Clients, Embedded Control, Mobile
Applications, GPS, and Interactive Kiosks to name a
few.
What is an embedded PC?
Embedded computers
usually operate out of sight and make technology work
for you. Embedded computers process information,
control machines and interact with people. They're
found in everything from aircraft to complex
machinery, and are used for a variety of applications
- from retrieving satellite data to controlling
manufacturing assembly lines.
What is Linux?
 Linux is an operating system that was initially created as a hobby by
a young student, Linus Torvalds, at the University of Helsinki in Finland.
Linus had an interest in Minix, a small UNIX system, and decided to
develop a system that exceeded the Minix standards. He began his work in
1991 when he released version 0.02 and worked steadily until 1994 when
version 1.0 of the Linux Kernel was released. The current full-featured
version is 2.4 (released January 2001) and development continues.
Linux is developed under the
GNU General
Public License and its source code is freely available to everyone.
This however, doesn't mean that Linux and its assorted
distributions are free -- companies and developers may charge money
for it as long as the source code remains available. Linux may be used for
a wide variety of purposes including networking, software development, and
as an end-user platform. Linux is often considered an excellent, low-cost
alternative to other more expensive operating systems.
Due to the very nature of Linux's functionality and availability, it has
become quite popular worldwide and a vast number of software programmers
have taken Linux's source code and adapted it to meet their individual
needs. At this time, there are dozens of ongoing projects for porting
Linux to various hardware configurations and purposes.
Linux has an official mascot, the Linux Penguin, which was selected by
Linus Torvalds to represent the image he associates with the operating
system he created.
Although many variations of the word Linux exist, it is most often
pronounced with a short " i " and with the first syllable stressed, as in
LIH-nucks.
Stealth configures systems with the Linux Operating Systems. Please
contact your account representative for further details.
What is Hyper-Threading Technology From INTEL?
Intel's next generation of Processors, fast and efficient
 Hyper-Threading
Technology is a groundbreaking innovation from Intel Corporation. Today's
software applications continue to put high demands on processor
performance. While running at a blazing-fast speed (2.60GHz, 2.80GHz,
3GHz, 3.2GHz with 800MHz FSB), Hyper-Threading Technology allows the
processor to function more efficiently when running multiple tasks at the
same time.
 Inside
each Intel processor is an instruction queue of actions waiting to be
completed. While one activity is being performed, Hyper-Threading
Technology uses idle processor sections to begin the next activity. This
efficient use of processing power enables you to work with multiple
applications more effectively; so more tasks can be done in less time.
This benefit is highlighted when several CPU-intense applications are
required to run together. Today with Hyper-Threading Technology,
processor-level threading can be utilized which offers more efficient use
of processor resources for greater parallelism and improved performance on
today's multi-threaded software.
Stealth's
Rack Mount and
Panel Mount PCs are available with Intel's new generation of
Microprocessors utilizing the Hyper-Thread Technology. Stealth offers
myriad of powerful computer systems designed for demanding 24/7
operations. Priced with-in your budget, Stealth Rack & Panel PC Warriors
are ideal for telephony, industrial control, plant automation, ISPs,
networking, machine vision, and data acquisition applications.
For a more detailed look at Hyper-Threading navigate to Intel's
Hyper-Threading area here.
http://www.intel.com/technology/hyperthread/
The SBC (Single Board Computer) vs.
motherboards
What are
the key advantages of using a SBC?
 Conventional desktop computers generally have most of their
electronics on a single large "motherboard" or "main board" that mounts to
the bottom of the computer's chassis. While this is the least expensive
packaging method, it leaves a lot to be desired when used in industrial
applications. Replacing a motherboard necessitates complete disassembly,
removing all cards and cables from the system. Downtime ranges from 30
minutes to several hours. This is unacceptable for many mission critical
applications where downtime can cost thousands of dollars per hour. Since
motherboard technology changes literally on a monthly basis, it is
sometimes impossible to find an exact replacement. Using another
motherboard often causes software problems due to BIOS changes, changing
device drivers, and different timing and interface issues. These can take
days or weeks to completely solve.
Another key area of concern is the availability of expansion slots. Many
of today's motherboard type systems do not offer as many ISA/PCI expansion
slots as they did in the past. In fact, the ISA slot has virtually
disappeared from the latest boards available today.
 Enter - the SBC
The Single Board Computer or SBC contains all the functionality of a
conventional motherboard only designed onto a single plug-in type card,
which looks similar to a standard ISA/ PCI card. This SBC plugs directly
into what is referred to as a "Passive Backplane". The Backplane is simply
a combination of ISA/PCI expansion slots into which the SBC and other
cards are inserted. There are many different configurations of Backplanes
available ranging from a couple of slots up to 20 or more.
Utilizing SBC and Backplane technology has several key and distinct
advantages.
-
Available ISA/PCI expansion slots for add-in cards
-
Lower mean time to repair (MTTR). System's can be upgraded or
repaired in seconds
-
Better configuration control and longer product life cycle and
technical support
-
Designed for 24 hour 7 day operation
For more information on Industrial Computer standards checkout PICMG at:
http://www.picmg.org
FAQ: What is a watchdog timer?
Move over rover let the watchdog take over
A watchdog timer is a piece of hardware, often built into a
Single Board
Computer (SBC) or embedded PC that can cause a reset when it determines
that the system has either hung up or is no longer executing the correct
sequence of code.
A properly designed watchdog mechanism should, at the very least, catch
events that hang the system. In electrically noisy environments, a power
glitch may corrupt the program counter, stack pointer, or data in RAM. The
software could crash, even if the code is completely bug free. This is
precisely the sort of transient failure that watchdogs will catch.
Bugs in software will cause systems to hang, therefore it is better to fix
the root cause rather than relying on a watchdog timer. In complex
embedded systems it may not be possible to guarantee that there are no
bugs, however by using a watchdog you can prevent those bugs from hanging
the system indefinitely.
Conclusion
A good watchdog system requires careful consideration of both software and
hardware. Make certain to decide early on in the design process how you
intend to use it and when a failure is detected you will reap the benefits
of a more robust system.
RIP - Death of The Floppy disc drive
Are reports of its demise greatly exaggerated?
 Now
ask yourself, when was the last time you used a floppy?
Floppy discs have been around since the 1970s and remain the oldest form
of low cost removable storage still around. In a sense, it's amazing
they have hung around for this long. They only hold 1.44 megabytes of
available space -- still enough for word processing docs but useful for
little else. By comparison, CDs store upward of 700 megabytes, DVDs are
4.7GB and the flash memory USB thumb drives typically carry between 16MB
up to 2.0GB
Now, there's nothing really novel about ditching the floppy drive; after
all, Apple Computer did it almost five years ago (heated reaction at the
time) with the release of the first iMac. For many the floppy has been
dead for some time now. Once email attachments became mainstream most of
us forgot they even existed. The floppy disc has several replacements;
including writeable compact discs,
USB/Firewire portable drives and the ever-popular
USB keychain flash
devices. All can hold much more data, are speedy to read/write data and
are less likely to break.
 Most
of Stealth systems today are shipped without the Floppy Drive. Many
small form factor PCs use the internal real estate for more
technologically advanced features. Having said that there are still
various legacy systems shipping from our factory with good ole Floppies
mounted proudly within. As with most technology transitions,
over time users figured out that they could do without. For now the
choice is still up to the end user to decide.
|
