Sign in with
Sign up | Sign in
Your question

How to fix a 486 dx

Last response: in Storage
Share
March 23, 2011 9:05:28 PM

Hello,I have an old 486 dx running at 66 mhz...Ahwile ago the hard drive crashed and the only way the machine NOW boots up is with a DOS floppy diskette 3.5 and THEN I still have to fake out the BIOS in the system and tell it the hard drive is way bigger than it is to get WINDOWS 3.1 to boot up. Once inside any applications that I was running won't run. I get invalid path or path not found messages. BUT when a DOS DIR command is entered all the files and paths are there. This is a real problem because I have a great deal of music on this computer (in sequences) which I have mabaged to get on to floppys and the FILES ONLY are now on my lap top. BUT I CAN'T GET THEM TO LOAD INTO ANYTHING MORE CURRENT. I NEED MY OLD MACHINE BACK to get these files re-saved into MIDI format so they will load into more current software. Already looked at the SPOTMAU program which is only on CD...If I thought the old computer would recognize a CD DRIVE I'd install one to be able to get it onto the old computer because it sounds like it would work? Any Ideas ANYONE? HELP?

More about : fix 486

a c 288 G Storage
March 24, 2011 4:47:05 AM

Can you explain what you mean by "crashed"? Is it an OS or hardware issue? What errors do you get during a normal HD bootup?

As for your "invalid path" errors, I suspect that there is a PATH environment variable in the AUTOEXEC.BAT file in the root directory of the hard drive. This statement would be missing from your boot diskette.

Can you explain the statement, "I still have to fake out the BIOS in the system and tell it the hard drive is way bigger than it is"? What is the model number of your HD, and how is it configured in your BIOS? Auto, User, LBA mode, Large mode, CHS mode?

BTW, I'm still running a 486DX2/66. :-)
m
0
l
a b G Storage
March 24, 2011 12:08:43 PM

Win 3.1 won't run when you boot off a floppy, too many subsystems from config.sys and autoexec.bat didn't run when you booted from the disk. I have had limited success in the past after booting a clean dos shell off a floppy disk (one with no config.sys or autoexec.bat) copying c:\config.sys c:\config.exe and then executing config.exe, then executing autoexec.bat This MIGHT give you an environment that windows will load up into after booting from the floppy.

Gosh, Its been years since I did any good DOS hacking - I may have to fire up the 8088 when I get home...
m
0
l
Related resources
March 29, 2011 6:44:50 AM

Regretfully after taking my computer to two different sources just to try to salvage the data on the hard drive now I can not even boot the machine from a floppy w/ DOS! Gibes me both HDD controller failure and FDD controller failure messages! I went in and saw the budd wasn't connected to the 3.5 floppy and placed the buss connector on it, and ALMOST wanted to work 1 time (actually lit up the drive LED)...Then nothing but the above messages come back. I unplugged and reseated all the internal buss cabling as i can see no corrosion on any of the pins and wanted to check them. Still nothing.

What i meant by the faking out the bios...w/ the drive specs is something I can not fathom. Because although I entered the correct info which is right on the top of the hard drive itself. This info continually gives the hard drive an amount of space IT NEVER HAD AND WAS NEVER FORMATTED FOR! It is the following: Cyln: 1001 Head:15 WPCOM: 0 Lzone: 0 Sect 34 BUT when the last value becomes added BY THE BIOS instead of the mere 40MB the drive was SUPPOSED to have, it reads 249MB???!!!
When i took this drive to the first source I tried for data recovery it would not even be recognized by the system the repairman was using. After the second try (which got at least to recognize the drive (this time at some 900 plus MB...) this repairman tried to fix the FAT and the boot partition...NADA...when he tried to just access data...It told him NO DATA FOUND! So now I'm wondering if ANYTHING is on it since I can't even boot up this machine with a floppy. I am at the end of my rope with this. Am having a friend of mine look around for a used 486 with the same configuration as what I had and will have to re-install Windows (3.1 if it doesn't come with it), and all my music software and midi interface and sound canvas controller software and HOPE that the files copied from my old diskettes to my lap top (for some kind of safe keeping) will work. I don't know what else to try as I have no one else to go to short of data recovery people advertising at overly inflated prices on line.
Make any sense at all? Any ideas other than what I've just explained. Thank you for your time and trouble. Sincerely.
m
0
l
a c 288 G Storage
March 31, 2011 6:56:12 AM

The BIOS is correctly computing the drive's capacity.

According to your CHS values, the capacity should be 261,381,120 bytes:
http://www.google.com/search?q=1001+x+15+x+34+x+512

It could be that the wrong CHS values were initially configured in the BIOS setup, and the drive may have been partitioned and formatted according to those values. Now that you are entering the correct values, they don't match the partition table and therefore the machine doesn't boot.

What is the model number of your drive?

Are you certain your floppy and hard drive cables are installed right way up?

BTW, I hope your "repairman" didn't write anything on the drive. :-(
m
0
l
!