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Chapter 3
BIOS Configuration
Gate A20 Option
Gate A20 refers to the way the system addresses memory above 1 MB
(extended memory). When set to Fast, the system chipset controls Gate A20.
When set to Normal, a pin in the keyboard controller controls Gate A20.
Setting Gate A20 to Fast improves system speed, particularly with OS/2 and
Windows.
Typematic Rate Setting
When Disabled, the following two items (Typematic Rate and Typematic
Delay) are irrelevant. Keystrokes repeat at a rate determined by the keyboard
controller in your system. When Enabled, you can select a typematic rate and
typematic delay.
Typematic Rate (Chars/Sec)
When the typematic rate setting is enabled, you can select a typematic rate
(the rate at which character repeats when you hold down a key) of 6, 8, 10,12,
15, 20, 24 or 30 characters per second.
Typematic Delay (Msec)
When the typematic rate setting is enabled, you can select a typematic delay
(the delay before key strokes begin to repeat) of 250, 500, 750 or 1000 millisec-
onds.
Security Option
If you have set a password, select whether the password is required every time
the System boots, or only when you enter Setup.
OS Select for DRAM > 64MB
Select OS2 only if you are running OS/2 operating system with greater than 64
MB of RAM on your system.
Video BIOS Shadow
Software that resides in a read-only memory (ROM) chip on a device is called
firmware. The EliteBIOS permits shadowing of firmware such as the system
BIOS, video BIOS, and similar operating instructions that come with some
expansion peripherals, such as, for example, a SCSI adaptor.
Shadowing copies firmware from ROM into system RAM, where the CPU can
read it through the 16-bit or 32-bit DRAM bus. Firmware not shadowed must
be read by the system through the 8-bit X-bus. Shadowing improves the
performance of the system BIOS and similar ROM firmware for expansion
peripherals, but it also reduces the amount of high memory (640 KB to 1 MB)
