Specifications

Computer Architecture and Maintenance (G-Scheme-2014)
It is sometimes up to 64K of real addresses but this is just a small portion of the whole
expanded memory, which can be very large. The expanded memory requires hardware
and/or software that maps the expanded memory to a piece of address space, in what is
called a "page frame". Extended memory can be used as expanded memory by using
software and the 80286 or 80386 chips to "remap" it to the lower 1MB. It should be
noted that the 80386 chip has hardware built in that supports expanded memory while
the 80286 chip does not. Software that will convert extended memory on an 80286
machine to expanded memory may result in a significant performance penalty, if the
machine does not have special hardware support for expanded memory. Software that
will convert extended memory to expanded memory on an 80286 machine is not
written to use the special hardware built into the 80386 chip, so the same type of
performance penalty may apply.
Hardware supported expanded memory is the fastest form of expanded memory
and is available directly on all 80386SX or better IBM compatibles running the proper
software. It is also available on some 80286 machines with special chip sets or 80286
machines equipped with a hardware memory manager add-on. Lastly, it is available in
a large number of memory expansion boards for all IBM compatible machines,
including the 8088/8086 machines.
BIOS-Basic Input Output System Setup
Q.What is Bios? State it Functions
Ans. The BIOS (basic input output system) provides the processor with the information
required to boot the system from a non volatile storage unit (HDD, FDD, Cdd or other).
It provides the system with the settings and resources that are available on the system.
BIOS (Basic Input Output System) is an electronic set of instructions that a
computer uses to successfully start operating. The BIOS is located on a chip inside of
the computer and is designed in a way that protects it from disk failure.
The four main functions of a PC BIOS
• POST - Test the computer hardware and make sure no errors exist before loading
the operating system. Additional information on the POST can be found on
our POST and Beep Codes page.
• Bootstrap Loader - Locate the operating system. If a capable operating system is
located, the BIOS will pass control to it.
• BIOS drivers - Low level drivers that give the computer basic operational control
over your computer's hardware.
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
86