How is the BIOS so small and yet can do so much?

  CurlyWhirly 18:39 12 Mar 2005

I have yesterday successfully flashed my BIOS for the first time and I had a very good reason for wanting to do this!
It wasn't as risky as it sounds, as I have a UPS and a Dual BIOS motherboard in case something goes wrong with the BIOS flash.

The actual BIOS update was downloaded and installed on to a floppy disk.
This was also the first time that I have ever used a floppy mainly because until this time I have had NO reason to use one, as they are virtually obselete!
I have come to the conclusion that my BIOS is only around 256kb in size, this is because when I opened up my drive A: (floppy disk) to view it's contents using Windows Explorer, the BIOS file was 256kb in size.

This doesn't seem that big considering how important the BIOS is, and all the menu options and configurations that are normally held there.
BIOS manufacturers sure fit a lot into a small space! LOL

  woodchip 18:46 12 Mar 2005

It's got to be small to fit in the memory, don't forget it depends on a button battery to keep it alive for up to about 8years even with the computer switched off. It consists of not one but many programs compiled in to the BIOS package

  woodchip 18:46 12 Mar 2005

CMOS memory that is, on the CMOS chip

  CurlyWhirly 18:57 12 Mar 2005

Thanks for that.
I had NO idea that the CMOS memory size was so limited as 256kb isn't much nowadays as Mb and Gb are the norm.
Also I had NO idea that the CMOS battery can last up to EIGHT years and that's with the PC off!

  FelixTCat 19:00 12 Mar 2005

It can also eat three Shredded Wheat at one sitting!

  CurlyWhirly 19:02 12 Mar 2005


  VoG II 19:14 12 Mar 2005

Some of us used to write pretty complex programs in *a lot* less space than that!

  justme 20:09 12 Mar 2005

Now you are bringing back memories.

If I remember right, most database programs (Dbase, Paradox etc) could be run from a 360K floppy disk and ran in the 'normal' 640K of memory found in most machine at the time.

These were fully functional programs which did almost everything the modern programs could but without the fancy graphics found in todays programs.

Modern bloatware is nice to look at, easy to use but is very big and resource hungry. Most newcomers to computing think that 512K memory and a 120GB hard disk are the minimum required to run programs.

  CurlyWhirly 20:12 12 Mar 2005

Some of us used to write pretty complex programs in *a lot* less space than that!

I didn't realise that you used to write your own programs.

  TomJerry 20:21 12 Mar 2005

induatry should have got ride of it years ago, but they did becuase so called "back-compitability"

the soon we get ride off it, the more advanced the computer can become

  FelixTCat 20:36 12 Mar 2005


My first computer only had 32 kbyte ROM and 16 kbyte RAM! I spent a fortune, for the time, buying another 32 kbyte of RAM (over £100). An 8 kbyte program was dangerously large.

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