Laptop

Laptop Sytem Components

Lower voltage results in lower power consumption which results in less heat.
Lower clock speed also results in less heat.
Lower voltage enables smaller rise time which enables higher clock speed. By instead using lower clock speed, the result is that lower voltage enables lower heat generation for this second reason, in addition to enabling lower heat generation by lowering power consumption.
Laptop: to check the battery: just charge it for 15 minutes with computer powered off. Then unplug the power cord to run the computer without AC — see if it runs. If it runs, the batteries hold at least some charge.
The battery meter (in the taskbar tray or under Control Panel > Power Options) is meaningful, and should be consulted, when the ac power is unplugged.
Do laptop battery calibration, to see how well the battery is working: You may need to first set all power management settings to "never shutdown," then fully charge the battery. Start computer in Safe mode, disable screensaver and with all all power management settings still set to “never,” unplug AC, and fully discharge the battery, timing how long this takes. Fully discharge means allow it to run all the way down until the computer shuts off automatically (at about 10% of charge). How long it takes to fully discharge gives you an idea of how good the battery is. Once the laptop battery has fully discharged, charge it back up again and restore the screensaver and power management settings.

Laptops generally accept PCMCIA cards
There are 3 PCMCIA card types. 1, 2, and 3.
They are all 54 mm wide and 85.6 mm deep (they go into the case a long way). They vary in thickness according to the type.
PC card is new name for pcmcia. Card that is hot swappable relies on socket services to be hot swappable. Typical uses:

G0 normal, G1 sleep, G2 soft off. Sleep modes (S), cpu states (C)
Global states: G0 is normal, full power, “hard on” - that’s my term. G1 is power-saving mode sleeping,
G1 has 4 submodes called Sleep modes, S1 – S3. Refer to various combos of cpu and memory states, once hd is powered down. Cpu states (C) refer to cpu alone. C0 (normal) to C3.
Higher number more savings.
S1. CPU is still on but not executing. Memory is still powered. Disks and other devices are powered down.
S2. Not typically used, cpu is powered down.
S3 windows standby mode, generic term is suspend to RAM: only the RAM has power.
S4 is hibernation in Windows, generic term is suspend to disk. hibefil.sys
G2 is soft off. (normal off)
G3 is mechanical off, hard off. Only clock and bios setup parameter chip (cmos chip) is running, on battery. Power cord can be removed.
CPU states:
C0 is normal. C3 is sleep cache flushed.. Between the 2 are lesser degrees of cpu off. C1 halt, wakes up fast.. C2 stop-clock, no clock cycles, takes longer to wake.
In short, standby is G1, S3; hibernation is G1, S4.

The Fn key is a special shift key that allows you to select alternative functions on F keys, as well as on some of the regular character keys. It internal functioning is slightly different than that of the other shift keys, in that the key combination sends out a completely different key code when the Fn key is depressed. The Fn key alone generally does not generate its own scan code. It is usually near the Ctrl key.
Typically Fn plus F1 or F2 allow you to control screen brighness. Fn-PgUp and Fn-PgDn — sound volume. Fn-Bksp toggles sound mute. Fn-F8 is often NumLock. Fn-F5 toggles display between builtin, external, and both. Fn-F12 – hibernate.