Looking for Flash Bios program!

Helder M. Vieira hmv at mail.telepac.pt
Sun Aug 24 08:57:03 EST 1997


I believe you are not familiar with microcomputer architecture. So, allow
me a (very) short explanation.

There is a tremendous magnitude difference between an application and
low-level machine commands. If a programmer had to control a floppy drive,
for instance, he would need a huge amount of code in his application. The
problem would be much greater if the programmer had to control every device
in the computer. And much, much greater, if he tried to include code to
control all varieties of devices from different manufacturers. Actually, an
impossible task.
So, computer code is usually divided in three main layers:

1. BIOS layer, the Basic Input/Output system. This is where almost all the
device control code is defined. It usually is in a PROM or EPROM chip. Like
all code, it may have bugs or may be redesigned for better performance. So,
more and more, it is being included in computers as FLASH BIOS, because
flash memory can easily be updated with new versions of code when needed.
Everytime you connect the computer, the BIOS executes a system checkup to
see if all devices are in good working condition. Information about the
exact kind of some of the devices installed in the computer lies in a
memory chip fed by a small battery. This way, if you change some device in
your computer (an HD, for instance), you can describe it's characteristics
to the BIOS, wich will save them in this chip. This is usally done using a
small BIOS routine (SETUP). If, for some reason, this information is lost,
the BIOS won't be able to recognize all the devices and the computer
probably won't work.

2. Operating system layer. This layer offers an abstract view of the
machine, using the BIOS services to control the real devices. For instance,
when an application needs to save data in a storage device, it might ask
the operating system to save it on the "D:" device. The operating system
knows if this device is a floppy, HD, tape or something else, and sends the
relevant commands to the BIOS. As the operating system is an abstract view
of the machine, several approaches are allowed, depending on the needs.
That's why you have several operating systems, each based in different
concepts (DOS, OS/2, Windows95, Unix,...)

3. Application layer. When you have a computational problem, you translate
it into some programming language, which in turn gets translated into
executable code (1's and 0's) by a compiler. The final product is your
application. When you need to run it, you use the operating system services
to load it into memory and monitor it's execution. During execution, all
input and output needed by the application is provided by a set of services
of the operating system. 


In your message, things are not very clear. If the BIOS in your machine is
built in an ordinary EPROM, it is almost impossible to destroy.
The usual cause of malfunction is the loss of configuration information in
the memory chip I mentioned above.
It is not practical to solve your problem by e-mail. Apparently, it is not
very serious, and could easily be solved by a professional.





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