Tuesday 23 December 2008

Super Unleaded Gasoline

Gasoline or petrol is a petroleum-derived liquid mixture used as a fuel in internal combustion engines.

Super unleaded gasoline has a higher octane rating for higher performance engines.

Sunday 23 November 2008

What is HDMI? What is HDCP?

HDMI which stands for High-Definition Multimedia Interface is an alternative to SCART (known as PĂ©ritel in France, trapezium shaped connector) and S-Video (analog video signal that carries the signal as two signals, luminance and color, round connector), for transmitted uncompressed digital streams.

HDMI connects digital AV sources to compatible output devices (e.g. television screens, computer screens), it's pure digital, no analog whatsoever. HDMI 1.0 was published in December 2002.

HDCP is the copy-protection scheme for HDMI initiated by Intel and Silicon Image.

Sunday 2 November 2008

What is WXGA?

WXGA is "wide" XGA, a non-standard resolution derived from the XGA, or Extended Graphics array, standard introduced by IBM in the 1990s - the hardware of which was developed in the UK (for an enumeration of computer display standards see wikipedia). WXGA uses a "widescreen" aspect ratio (ratio of long side to the short side of a display unit).

Metrics for WXGA hardward include luminance in "nits" (an American term for candela per square meters (cd/m^2)); the word derives from the latin nitere (to shine). An average cloudy sky is about 2000 nits, an average laptop screen is about 10 % of that at 200 nits. The moon's surface is about 2500 nits, over ten times brighter than the average laptop screen.

Luminance is also known as luminous intensity or photometric brightness.

Thursday 30 October 2008

What is DIMM?

DIMM is dual in-line memory module, consisting of DRAM circuits. The successor to Single in-line memory modules, or SIMMs.

Standard SIMMs have a 32-bit data path while standard DIMMs have a 64-bit data path. This is suitable for the Intel Pentium which has a 64-bit bus.

Tuesday 28 October 2008

DRAM 101

Everyone knows intuitively that RAM is computer "memory" that allows "random access" (access any location in memory in any order in constant time). RAM normally refers to volatile memory where information is lost when power is turned off.

But what is the difference between dynamic and static RAM? In static RAM, an electronic component known as a flip-flop (aka bistable (Two State) multivibrator) stores 1 bit of memory, in DRAM this bit is stored instead as charge on a capacitor or transistor gate.

The physical implementation of flip-flops is covered here.

Saturday 23 August 2008

Digital Camera Terminology Explained

PictBridge is an industry standard from CIPA for printing images from digital camera to printer. Created in 2003.

CIPA = Camera and Imaging Products Association

SLR stands for single-lens reflex. Meant to offer better WYSIWIG photography. SLRs were apparently initally developed for large-format photography.

What is 3GP?

3GP is a simplified form of MPEG-4 for 3G mobiles.

Saturday 9 August 2008

What is BS6206?

This is a British standard for safety glass.

Class A - Toughened/tempered glass
Class B - Two sheets of ordinary glass sandwiching a plastic inner layer
Class C - Wired (Pyroshield) glass. Can be clear or textured.

Friday 8 August 2008

What is Intel Core2 technology?

http://developer.intel.com/products/processor/core2xe/index.htm

The Intel Core2 is built using a technology called Micro-FCPGA (Flip Chip Pin Grid Array). In this architecture the die (small block of semiconducting material) faces downward on top of the CPU with the back of the die exposed. This is to allow the die greater contact with the heatsink.

What is DLNA-certification?

A lot of laptops these days have the sticker "DLNA certified". What does this mean?

DLNA is the Digital Living Network Alliance. DLNA compliance enables your laptop to be used as a digital media server.

What is an Ingress Protection rating?

An IP rating (or IP code stands) for "Ingress Protection Rating" which classifies the level of protection electrical appliances have against intrusion of solid objects, dust and water.

The standard aims to provide more information than simple "waterproof".

The first digit indicates the amount of protection against solid objects.

The second digit indicates the protection of the equipment inside against various forms of moisture.

e.g. an IP65 halogen shower light will have a protection-versus-solids rating of 6, which indicates its dust-tight, and protection-versus-moisture means protection from water projected from a nozzle. IP67 would mean protection against immersion in water, and 68 would be complete continuous immersion in water (but submersion depth and time must be specified).