Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I have a question that I had been wondering about ever since my first OS freeze due to an attempt to read a floppy from a drive that doesn't exist. Why do operating systems even try that? Isn't it possible for them to detect the absence of a drive connected to the motherboard?

share|improve this question
3  
A floppy is just a device. What operating system are we talking about. Most modern operating systems actually have this protection –  Ramhound Jan 26 at 2:11
    
I had the same problem with both Linux and MS Windows - try to read from /dev/fd0 or open disk A: in Windows when BIOS is not configured properly and you'll see what I mean. –  d33tah Jan 26 at 2:12
    
What does the hard drive have on it right now Windows or Linux and which version? If linux uname -r post results. –  cybernard Jan 26 at 2:54
    
I don't have an A drive. Even when I did the problem you describe wouldn't happen –  Ramhound Jan 26 at 3:27

2 Answers 2

The way the old floppy drives work were not directly controlled by the OS, but rather by specialized hardware called a floppy disk controller. The operating system would request to read from a floppy disk with the floppy controller, and if there was no floppy disk connected, the controller would stall for quite a while waiting for signal to come back, thus causing the operating system to appear frozen. The operating system would have no control over this process, and thus there was no way to avoid it being frozen.

The reason for this is because floppy drive hardware stems largely from the 1970s, an era where hardware was really expensive. Adding functionality into the chip to detect if the floppy wasn't there was simply too expensive, so it just always assumed that the floppy disk was there in order to remain cost-effective. This is why you would have to specify which floppy disk drives were actually present in the BIOS. This aspect of legacy hardware lasted all throughout the floppy disks life because to change the IBM floppy drive hardware standards would break compatability with different operating systems.

share|improve this answer

Usually there is no issue that I know of if floppy seek is disabled in the BIOS. With the many computers I have worked on, the error caused by the non existant floppy drive was corrected by changing it in the BIOS.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

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