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nyt

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Hard disk and BIOS

Hi,
I got a 486 from my friend and it's for my kids to play with.  However I have the following problem when setting up the HDD.
The HDD is about 850MB.  But when I format it in DOS, the DOS can only format the hard disk to 504MB.  I suppose this is because of the old BIOS, but the BIOS can recognize the HDD as 8xx MB in the bootup setup.
How can I install the 850MB HDD in the 486?  I have heard of that Win9x uses its own BIOS and supports large harddisks in old computers, any one has such experiences?
Thank you!!
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j2
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Use fdisk and make 2 drives out it. Format each one separtely. You willhave a C: amd a D: drive.
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puddin00

also try to do a fdisk /mbr from an aprompt and then do a fdisk on the machine from the a prompt. when you get to the fdisk option hit 4 and find out what type of partition you have and how many. then hit esc, the go to option 3 i think it is to delete the proper partions. then reboot and format the drive and then try it might work for you.
What version of dos do you have?
if you have an old version it might not let you format the whole drive.
If you can get a boot disk of dos (5.0+) or Win95 you should be able to format the whole drive.
What kind of drive do you have?
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Try using ez-drive to setup the drive http://www.tekwarecomputers.com/download/ezdrive9.exe and have it install EZ-BIOS.  EZ-BIOS is an overlay software that will overcome any BIOS limitations.  Worth a try.
joed, along his lines of thinking, is it possible that you have only formated it and not used fdisk at all, and therefore there still may be some remaining data to be used on the hard disk, IE the other 300 meg? it may have been setup up like that since the computer was built....

run fdisk, goto option 4 and see what it says, it may say something like only 70% of your hard disk may have been used, in which case simply create an extended partition and it will appear as drive d: you could try something like partition magic (if its this problem) and merge the data into drive C.....

Good luck and hope that helps if its the case.

Craig C.
YOU need to fdisk from a win95 disk.  The win95 version and later of FDISK will create the maximum size partition that you want.
If you want to recover data don't do anything. You could be writing over data.
Get a data recovery program and run it. I have seen some links in previous posts but didn't mark them down.
I had this problem on a couple of computers in my plant.  It usually stemmed from the hard drive being compressed in a previous installation.  The first thing to do would be to make sure that you have all of the settings correct in your CMOS.  Look at the hard drive and compare the heads, sectors, etc to what it says in the CMOS set up for the drive.  Also look at the mode that the drive is in.  If all is set correctly, the CMOS should reflect the proper drive size in the set up.  Sometimes I've had to play with these settings to get the proper disk size.  Another option is that the disk was compressed in a previous life.  Try running fdisk /mbr to restore the master boot record, then run fdisk to create the partition and see what size you get.  It's a weird one...I'll grant you that.

Good Luck
whats so wierd about an old system not accepting anything larger then a IDE drive? 504Mbyte (528482304) should be familiar numbers to all "oldtimers" out there :)
"Win9x uses its own BIOS and supports large harddisks in old computers, any one has such experiences? "

No it doesnt.

Linux and NT does (well the correct phrase is _ignores_ the BIOS), but that will not work for a boot device, and only if the controler supports the disk, and the problem is _just_ in the bios.
j2,

Nothing weird about the hardware.  I work with antiques (4-10 year old computers) everyday.  The weirdness is in the differing size between the actual hard drive and what the system sees. ;o)
Why?

If your controllers only support "plain IDE" it cannot display a value larger then 504Mbyte. Simple math.
The real fun ones are the old buggy controllers, in which the registers rolled over when a parameter owerflowed, you could get all sorts of funky sizes then.

Ok, thats besides the point. :)
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ASKER

Hi all,
I will try the suggestions by you experts soon.  Thanks for all your suggestions!!
Check the system BIOS for a LBA support option.  Turn it on if you hdo have it.  You may be able to check for an updated version of BIOS for the system that does have this support.  Short of this, the drive will be 504MB. (without other hardware, or a third party utility)