Portable PC’s Chapter 18

History/Background Problems with making PC’s mobile – Not enough power in batteries Early PC’s only had plugs, no batteries – Ensure reliability PC parts were not designed to be bumped around Some of the first mobile PC’s had shock absorbers – Functionality How could you use a mouse, other parts of the PC that weren’t so easy to use with a mobile PC

Luggables The first portable PC’s were “suitcase luggable” – Weighed up to 40 pounds – No batteries, could only be plugged in First luggable was the Osborne One, but wasn’t considered a PC, because it was not compatible with IBM’s BIOS Compaq came out with the first true portable PC

Laptops 2 separate technologies that allowed PCs to become truly portable – Nickel-Cadmium batteries provided constant voltage – Liquid Crystal Display (LCD) You could only have a 4” to 6” CRT because of the tubes and the weight. STN (super twist nematic) allowed LCD to become quicker and keep up with the demands of the PC

Laptops/Notebooks Zenith first combined a Ni-Cad battery and LCD display with a mobile computer. – Picture on 1078 When the laptop was made even smaller to fit into briefcases it was then that they got the name “notebooks”

Personal Digital Assistants This is the actual term for what most people no as Palm Pilots, or handhelds. PDA’s used to have a little keyboard, but now use “pen-based computing”

Batteries Nickel Cadmium (Ni-Cad) – First batteries commonly used in mobile PCs – One problem was with “battery memory”, the tendency for it to lose a significant amount of its rechargeability it was recharged completely without being totally discharged – Would last for a max of about 1000 charges – Very susceptible to heat – Be careful when disposing of them

Batteries Nickel Metal Hydride (Ni-MH) – The answer to Ni-Cad’s problems – Are still quite common today – Can tolerate overheating, last longer between recharges, and take more recharges

Batteries Lithium Ion (Li-Ion) – Most common type of battery used today – Completely immune to memory problems and last at least twice as long as comparable Ni-MH batteries on one charge. – They can’t handle as many charges as Ni-MH though. – Can’t be used as replacement batteries

Batteries Smart batteries – A new type of battery that tells the computer when they need to be charged, conditioned, or replaced.

Batteries Always store batteries in a cool place Condition your Ni-Cad and Ni-MH batteries Keep battery contacts clean with a little alcohol or a dry cloth Never handle a ruptured or broken battery Always recycle old batteries

PC Cards Used to be known as PCMCIA Know the 3 sizes – Type I – 3.3mm - Memory – Type II - 5 mm - NICS and Modems – Type III Hard drives Type II are by far the most common, so most laptops will have 2 type II slots

PC Cards There are two levels of software drivers to support PC cards – Socket services – device drivers that support the PC card socket; I/O, IRQ – Card services – recognizes the function of a particular PC card There is something called CardBus that is out now that has several advantages over normal PC cards (1088)

USB In theory up to 127 devices may use a single USB port In reality its throughput of 12 Mb/s limit it to about 3 or 4 devices They run at 2 speeds: 1.5 Mb/s or 12 Mb/s Allows for a maximum cable length of 5 meters; you can use a USB hub to extend the distance

USB Configuration Follow these steps when configuring – Be sure that the CMOS provides for an IRQ for the USB ports – Ensure that your OS supports USB – Always install the device driver for a new device BEFORE you plug it in

Basic Parts RAM – Every decent laptop has upgradeable RAM slots. SO-DIMMs 72 or 144 pin. Hard drives – ATA drives in the 2.5 inch drive format are most common in laptops Video cards – Not very standard, but are becoming more popular

Power Management The process of cooperation between the hardware, the BIOS, and the OS to reduce power use. APM/ACPI – Standards that allow a specialized BIOS and OS to perform power management ( )