“The semiconductor density is the driving force, and as you reach new densities, new machines pop out.” Gordon Bell.

Advances in chip density made an impact on calculators.

Notable are HP-65, programmable calculators, introduced as a personal computer.

• Created a market with long production runs, thereby getting economies of scale and low price.

• First consumer market for logic chips.

• Unleasher creative force among users.

• Led to the rise of “hacker culture” of MIT.

• Led to the rise of user groups, support magazines etc, indicating that computingwas a mass phenomenon, as HP could not afford a trained sales force which could train customers to get the best out of the product.

• This kind of supporting infrastructure would later become critical to the industry,and become an industry on its own.

The Microprocessor

• Gordon Moore, founder of Intel, noted that the number of transistors that one could place on a single chip, doubled every year.

• If enough transistors were placed on a single chip, it would make a generalcomputer

• 1971, the first microprocessor was developed at Intel.

• A general purpose chip with a few instructions, and most other operations realised by a combination of these instructions.

The role of hobbyists

• Hobbyists played a key role in the development of the computing industry.

• They made the microprocessor based systems practical.

• A magazine announced a $400 kit, which one could assemble into a computer.

• Once again this inspired extensive user support, and the lack of certain capabilities inspired certain innovations, like the floppy disks.

• BASIC was deverloped to fit into little memory, and yet gave impressive performance

Augmenting Human Intellect

• DEC bet the company on the VAX, with a virtual memory, and MIPS, which became a benchmark

• POTS to OLTP -> a use of terminals for online access appeared, tailored for specific applications. Like the SABRE.

• Wang Labs, paved the way for office automation, by developing word processing softwares.

• Xerox PARC. Research done at the labs, defined interactive computing as we know it today. The Mouse, WIMP.

• The move of research from universities to PARC, forced cost and marketing onto the products.

• Steve Jobs and Wozniak developed the Apple II, which was one of the first instances where aesthetic considerations influenced design.

• IBM PC influenced MS-DOS

The Clones.

• Compaq, developed an IBM Compatible portable computer

• Phoenix made an IBM Compatibe bios chip.

• Soon, Dell and compaq would make more money selling IBM Compatible machines than IBM would

• The winner was MS, selling software to all.

• This era brought S/w to the fore. H/w no longer became the driving force Of computing.

UNIX and the NET

• UNIX, developed at AT & T Bell labs, became the main reason for the eclipsing of mainframes and minicomputers.

• Provided an alternative to those ancient elephants. Small computers, networkedTogether, would provide an alternative to those machines.

• The network was the Ethernet, developed at PARC.

• DEC, once again bet the company on VAX. Provided the VAX with small computers networked together.

• DEC phased out the PDP-10.

RISC Architectures.

Henessey and Patterson, developed the architecture.

• Small number of instructions offered a way of improving processor speed.

• SUN SPARC overcame any skepticism of the RISC.

• With this, SUN took the advantage open systems, general purpose machines,Offering good performance at low prices.

Ethernet.

• Enabled the introduction of LAN’s, which paved the way for the PC to completely Invade the corporate offices.

• The internet. Descended from ARPAnet. Funding was from the ARPA and NSF.

• GOPHER -> first routing protocol.

• Mosaic -> Browser.

Further developments.

HTML, HTTP, www, hypertext.

The internet is often described as the culmination of all developments in computing.