While battery technology made tortoise-like slow-and-steady progress, laptop power requirements continued to hare forward. Low-powered monochrome LCD screens were replaced by colour TFTs, hard drives were added and processor speeds were rocketing.
In fact in the late Eighties it all got too much for the humble battery technology of the time, and processors in laptops hit a glass ceiling. As desktop machines raced ahead with the 386 and 486 DX processors, laptops such as Compaq's LTE 286 were stuck using the much slower 286 due to the high power demands of the newer models.
This marked the end of an era in laptop design, when it was all about squeezing desktops into smaller boxes. The arrival of Intel's 20MHz 386SL processor, first announced in 1990, based on the 386 SX core, heralded the beginning of another.
It was the first major product to come out of Intel's mobile division, set up in 1989, and the first CPU to be designed specifically with mobile computing in mind, featuring power management features and sleep modes to conserve battery life. It was a big success, with many major manufacturers adopting the new processor.
But despite the success of the notebook specific 386 and its successor, the 486SL, mobile processor design went backwards in the mid-nineties with the arrival of the first Intel Pentium processors.
AMD, Intel's big rival in the processor market at the time, didn't seem bothered (it didn't produce a mobile-specific processor until 1999). And despite the continuing availability of mobile-specific equivalents from Intel, many manufacturers still opted to squeeze the cheaper, non-mobile products into their laptops.
*Image courtesy of Andrew Dunn.