Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top


The question was directed to the first attempt of creating a BIOS (Basic Input/Output System).

Simply, the first "thing", to have the first "function", when it is not written in an operating system already.

They may be using machines, to have the display turn its colors. Then to showcase a symbol. Which then may continue into a character set. The switching of symbols, or also pages may become possible. The setting of different colors may become possible. And then it may continue taking forms into a BIOS system.

I have rewritten this one more time, nevertheless, I am having troubles to formulate on this topic, it can be considered as resolved.

share|improve this question

closed as not a real question by Leon Heller, Dave Tweed, Olin Lathrop, The Photon, Brian Carlton Nov 5 '12 at 22:08

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

I don't understand what you are asking. Is your question about the low-level working of a computer, or about how one develops an OS, or something else entirely? The addendum and the last part of the question only add to the confusion. – Wouter van Ooijen Nov 3 '12 at 10:04
Please consider restructuring the question to specifically address the Electronics question you want to ask. This is too confusing. – Anindo Ghosh Nov 3 '12 at 10:17
You will probably get further looking at actual cases of modern embedded operating systems and associated bootloaders, historic BIOSs, and modern BIOS replacements than in sticking to some theoretical "action and function" model of what you expect to find. It's not that the theoretical model doesn't have validity, but you need to understand something about the realities of possible implementation before it will have enough context. – Chris Stratton Nov 3 '12 at 14:41
I have tried reformulated the question. I am having troubles formulating and articulating on this topic. The question is indeed directed at the first "thing" which is done to manage the first ´function´ and take it further till to an action BIOS system - when it is not done in Windows. – user1778219 Nov 3 '12 at 18:05
In the above comment "actual BIOS system" was meant. – user1778219 Nov 3 '12 at 18:12

The term BIOS originated with CP/M back in the 1970's but it is mostly associated with the IBM PC (1981) and its various clones and successors.

The BIOS gets control when the computer first starts up, via the reset vector of the processor at f000h:ffffh (or is rebooted using the Ctrl-Alt-Del key combination).

The BIOS then does a POST (Power On Self Test) which verifies the processor, various peripherals such as DMA, interrupt controller, and main memory are okay, and that there is a keyboard present.

In the original IBM PC there were no floppy disks, so the BIOS provided routines to interface with a cassette drive. A year or so later, floppy disks were added and the BIOS was upgraded to provide various functions such as formatting a disk, reading and writing sectors, etc.

Once the POST was finished, the BIOS would use its own disk routines to read in the first sector of the disk which contains the boot code -- this is then used to load in the operating system (e.g. MS-DOS, and later Windows).

Once MS-DOS was loaded in, the BIOS provided functions to interface with the video display, disk drives, serial ports, printer ports, keyboard, and real-time clock and other hardware. The interface was done via software interrupts -- for example, INT 10h was used for video, and INT 13h was used for floppy disk services.

Later, routines were added to detect PS/2 keyboards and mice, and still later, USB keyboards and mice during boot-up. Likewise, the floppy disk routines were enhanced to interface hard drives, then CD/DVD drives, and finally USB flash drives as boot options.

The original 16-bit versions of Windows (which essentially sat on top of MS-DOS) also made use of BIOS services. 32-bit versions of Windows have their own I/O routines and do not use BIOS services.

So by the definition of the BIOS given above, this is not really a OS, but just I/O routines which provide services to an OS (hence the name Basic Input/Output System). To have a minimal disk OS, you would need to add a file system and the ability to run programs off of disk. (The command line interpreter would be loaded off of disk when the OS starts up.) These functions could be included in the BIOS, but it is better to keep it as minimal as possible.

share|improve this answer
Thanks a lot for the run down. To extend the asked question a bit. I do draw the analogy to audio frequencies, where a certain constellation of frequency waves in a specific range may cause a tone, which then can have its definition. It may have a similar principle with electricity where certain constellation may cause something specific to happen, when then again may have its own definition and perhaps a hardware button representing it. Till it does move into a user interface which does get controlled with a mouse. Yet, I am wondering if this procedure can be quick.(?) – user1778219 Nov 3 '12 at 7:43
I have rewritten it one more time, it can be considered as resolved. I had troubles tapping out this topic and would consequently mess up the writing. The making up of attributes and concluding in "something", was meant with the incorrectly used word "constellations". – user1778219 Nov 3 '12 at 19:44
"Contestallations" would be obscure though not incorrect terminology - we might be more inclined to say input vector. The real issue though is that is an almost mathematical view of a system, while the questions you are asking are all about implementation detail. – Chris Stratton Nov 4 '12 at 0:04
The barrier is indeed one, to be crossed. Where, the information mentioned in this thread have contributed to have the barrier more outlined and better understood. – user1778219 Nov 4 '12 at 1:37

Not the answer you're looking for? Browse other questions tagged or ask your own question.