PCs themselves became so ingrained in our world that the information technology profession began looking to a "post-PC era." Thanks to continued improvements in microprocessor power, starting in 1993 with Intel's Pentium and its 3.1 million transistors, PCs had become incredibly powerful. Gains in battery technology, power management techniques, and display technology brought a procession of smaller, lighter portables.
But despite the fact that PCs could—and did—go with us just about everywhere, the search for alternatives that would launch that "post-PC era" was on. PDAs sprouted from jacket pockets, some of which began offering wireless links to e-mail and the Web. As time went by, some PDAs looked more like phones, while phones often crossed over to PDA-like functionality.
Throughout the decade, portable devices gained more functionality. Simultaneously, they shrank and benefited from elongated battery life. Advances in power management ICs stemmed from myriad variations on the theme of pulse-width modulation (PWM), including switching regulators and low-dropout regulators that contributed greatly to the runtime of portables.
Cellular telephones likewise benefited from improvements in MOSFET efficiency and gain as a new generation of power transistors took over RF applications. Equally critical in the development of cellular handsets and other portable systems were improvements in packaging technology, with ball-grid array and chip-scale IC packages coming into prominence.
Alongside the evolution of microprocessors during the nineties, other highly integrated ICs evolved as well. Thanks to the development of logic synthesis technology, the ASIC business model developed in which circuits could be built for highly specific applications. By 1993, IBM had moved past the million-gate chip level in density. Three years later, gallium-arsenide (GaAs) gate arrays hit the 100-kgate mark.
On the programmable logic front, progress also came quickly. Xilinx had invented and pioneered FPGA technology in the latter half of the eighties. Then, Actel launched antifuse technology in 1991. Programmable devices soon became an important means of prototyping logic circuits before committing them to the long and costly design cycle associated with ASICs. FPGAs with dedicated blocks of RAM appeared in 1995, while embedded processors made their debut on programmable devices in 1997. By the end of the nineties, FPGAs had reached mega-gate densities.
As deep-submicron geometries shrank to 0.5 microns and smaller, silicon integration enabled designers to begin working toward entire systems—processors, cache memories, and all associated peripherals and interface logic—on a single chip. The system-on-a-chip (SoC) concept took hold, particularly with the rise of fabless semiconductor vendors such as ARM, which developed embedded processors that were marketed as intellectual property rather than as fabricated silicon devices. Embedded DSP cores debuted as well. Underlying the development of SoCs was an improving design automation infrastructure, which became increasingly capable of pulling together diverse IP blocks and verifying that they functioned as they should.
Analog circuitry enjoyed gains during the nineties too. Delta-sigma analog-to-digital converters rose to prominence among conversion technologies for digital audio applications. Digital-to-analog conversion rose to the challenge of cellular basestations, PC graphics, set-top boxes, and other circuits requiring high accuracy.
Memory technology came along for the ride. Densities ballooned from 64 Mbits to 256 Mbits for DRAMs. At the same time, they became much less expensive, allowing for system integrators to take advantage at minimal cost. Storage technology also evolved, with compact discs becoming first writable and then rewritable.
By its close, the nineties had shaped up as a decade of digitization. The music industry had fully embraced digital technology, both for creation and distribution of content. Digital cameras, both still and video, were all the rage. Phones had gone digital, as had some television broadcasting.
As the new millennium approached, however, a uniquely digital problem cropped up. Back in 1968, an obscure federal standard had codified the six-digit data format (YYMMDD) for information interchange, sowing the seeds of the Y2K crisis. Millions held their breath on New Year's Eve as 1999 rolled over into 2000, wondering if all the traffic lights would stay stuck on red because the computers that controlled them had crashed.
But they didn't. The dike held, the flood was turned back, and the technology proved more robust than the doubters thought. The digital revolution was complete and had its vindication to boot.
Click here for several examples of the special photos in this picture album.
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