Information Technology
![]()
Network Computers
- Over last 20 years, microcomputer explosion has moved from computing from centralised systems with dumb terminals towards personal computing
- Might start going the other way soon - 'Network Computer' philosophy being mooted
- NC is not a dumb terminal - full PC - but lacks any sort of data storage (HD/FD) facility
- Relies entirely on Internet Connections - storage is handled remotely
- Based around Web Browser Software, running Java Programs
- Big money behind the idea at the moment - first NCs are now available
- But may not ever take off (Hard disks are very convenient to have)
Storage Devices
Removable Media - 'Superfloppies'
- Current 1.44Mb floppy disks outdated
- Higher density 2.88Mb floppy disks exist - but haven't really taken off
- Floppy disks are:
- Slow
- Have little storage space
- Error Prone
- Pressing need for replacement with high access speeds and capacity in 100's of Mb
- Several contenders exist in the 'superfloppy' market:
- Currently unclear which (if any) will emerge as new standard
CD-R
- Covered in Storage Devices Lecture
- Advantages:
- Media fairly cheap
- Storage capacity high (650MB)
- Durable
- Can be read by now near-standard CD-ROM drives
Other WORM and fully erasable optical formats
- Several exist. Nothing standard emerged yet.
- All expensive, but all higher storage capacity than CD-R
- Not readable by ordinary CD-ROM drives
Hard Disk Cartridges
- Have been around for a long while - especially on Macs ('Syquest' disks)
- Use small removable hard disk cartridges - various capacities
- Several competing systems on PC market at present (e.g. Zip drives, .)
- Advantages:
- Fast
- Drives fairly cheap
- Erasable - not WORM
- Disadvantages
- Disks relatively expensive
- Capacities not as high as CD
- Incompatible with each other
Floptical disks - magnetic storage, optical tracking
- Use normal type (though better quality) floppy disks
- Store information magnetically
- Locate information with high resolution optical system - very accurate
- Advantages:
- Can read old style floppies
- Drives fairly cheap
- Erasable - not WORM
- Disadvantages
- Capacities relatively low (<100Mb)
- Slow data access
EEPROM memory
- Solid state devices - form of ROM that can be rewritten
- Advantages:
- VERY Fast (especially for reading)
- Reliable, and rugged
- Erasable - not WORM
- Can be used in laptop PCMCIA slots
- Disadvantages
- Low Capacities - <10Mb
- Expensive
- Its time has probably yet to come
Main Storage
- Hard disks only form of main storage at present
- High densities, fast access speeds, fairly low cost
- BUT
- Moving parts- they wear out, and have high power consumption
- Maximum magnetic densities are being approached
- There is a long term need for alternative devices to provide fast long term storage, with very large capacities
- Possible future for EEPROM devices (see above) as main store if prices fall enough
- Access as fast as main memory
- Easy to expand storage by just adding more chips
- Current devices such as Hard Disks 2D - store information on a surface - limited.
- Future (10 years or so hence) probably lies with 3D solid state storage devices
- Various 3D devices are in development, notably:
- Holographic cubes
- Store information as interference patterns of light
- Read and written by lasers.
- Have been built - storage capacities still low.
- Potentially very fast, packing a lot of information into a small space.
- Molecular/crystal storage devices
- Store information in a 3D array of molecules arranged as a crystal
- Special molecules can be set to two states with exact frequencies of laser light
- State can be 'read' with another frequency of light
- Would enable VERY densely packed storage and VERY fast access
- Still at theoretical stage
Processors
- Microprocessor development has been relentless over last 20 years
- Moore's Law - processor speed doubles every two years - roughly held true
- BUT - Theoretic limits of miniaturisation with current technology may be within sight
- Speed may yet increase to several billion instructions per second
- Will probably then start to level out
- Most potential at present seems to be with RISC chips
- Intel x86 line may be running out of steam
- Limits of design improvements with this old instruction set may be in sight
- Miniaturisation improvements will continue to speed things up though
- Attempts to change x86 line to 'CRISC' designs only a partial solution
- MAY mean that the future of PCs lies in some eventual transfer to different CPU type
- Hard to see how this could happen in practice
New processor technologies may delay or avoid the crumbling of Moore's Law:
GaAs (Gallium Arsenide) chips
- Similar sort of thing to silicon
- Can move impulses faster
- Can operate at higher temperatures (thus circuits can be closer packed)
- Devices already exist - still specialised - but could supplant Silicon eventually
Superconductors
- Superconductors are materials that conduct electricity with no resistance
- Thus generate no heat - circuits can be packed together as close as physically possible
- Most materials only superconduct at very low temperatures (around -250C)
- Recent research has produced superconducting materials that work at much higher (but still very subzero) temperatures
- IF (big if) room temperature superconductors are ever produced - could be used to make superfast processors consuming virtually no power
Vacuum Tubes!
- 1950's computers based around vacuum tubes - now obsolete of course
- Chips could in theory be made with microscopic vacuum tubes rather than transistors
- Electrons move faster through vacuum - devices could in theory be 1000 times faster than Silicon based equivalents
- Currently still theoretical
'Photonics'
- All current computing devices work with electrical impulses
- In theory - can build a device that uses light impulses instead
- Light travels at the speed of light (obviously) - as fast as you can get
- No heat generation problems
- Would work easily with optical storage devices and optical transmission method (optic fibres)
- Could interface fairly easily with electronic devices as well
- A lot of research has been put into 'photonics' - no obvious payoff yet - but watch this space!
'Biochips'
- Possibility has been aired of 'chips' grown biologically
- Would consist of chains of molecules carrying electronic signals
- Could be made very compact, and could in theory interact with biological systems - many medical applications
- Still very hard to make in practice - but progress is being made
Input and Output
Speech recognition systems - the end of the keyboard?
- Concept as old as the electronic computer - input via speech rather than keyboard
- Only really become practical recently - needs lots of processor work to recognise speech
- Still (and possibly always) imperfect - but already useful in some applications
- Effective speech recognition would enable further miniaturisation of computers
- Might also make them more user friendly
- BUT - would make computer labs impossible - would be surrounded by people talking!
- Will probably remain a specialised input method for a good while yet - if not always
Future of output - electronic paper? The Electronic book?
- Flat screens have more potential than CRT based displays
- 5 years hence - TFT screens or something similar will probably be used on most systems
- Technology for paper like screens is currently being developed
- Might eventually enable electronic paper - could make printers and any form of 'hard copy' redundant
- Future computers (a long way off) with voice control and thin screen output - might look like and replace books
Virtual Reality
- Idea of VR is to provide input to as many senses as possible and exclude the real world
- Immerse the user in an artificial environment simulated by the computer
- Take input directly from movements of hands, head etc., feed into simulation
- Associated input devices built as sensory body suits to detect motion
- Output devices:
- Headset with small flat screen displays on eyepieces
- Audio input from headphones
- Sometimes tactile output from gloves
- Despite the hype, still very hard to do well
- Need a lot of computing power to simulate environments well
- Bodysuits still rather crude
- Eyepieces cause headaches - can't cope with human focusing mechanism
- Potential applications
- Entertainment
- Training for real world tasks
- Front end for computing systems?
Artificial Intelligence
- Intelligence not well defined - tend to define intelligence as thinking like we do
- Artificial intelligence then (probably) involves building a computer than works in the same manner as the brain
- Brains work on an completely different principle to computers - they are 'neural networks'
- Computers - one complex central processing unit performing well defined sequential instructions
- Neural Nets - countless very simple cells linked together in intricate ways to process data
- Intelligence is thus a property of such a neural network system
- Neural nets are fuzzy, vague things, unlike sequential computers
- Good at giving best guess sort of answers to complex problems
- Poor at performing even simple tasks precisely
- Computers CAN simulate neural networks - by dealing with each cell in turn
- Too slow to simulate a brain (with hundreds of billions of cells)
- But can run simpler neural nets - have been used for applications like object recognition
- Supercomputers of the future could in theory simulate a large enough neural network for intelligence - but problem of how to connect it up is at least as daunting
- Why try to force a computer to be 'intelligent' and act like a human?
- Better to get computers to do the things we can't do - the key to their success!
Go to Top
![]()
![]()
Comments, criticisms, suggestions, and additions welcome! E-mail Dan Fournel at [email protected]
Best experienced with
Click here to start. Microsoft is a registered trademark and the Microsoft Internet Explorer Logo is a trademark of Microsoft
This page was last edited on: June 08, 2000
Go to Top