We help IT Professionals succeed at work.

Check out our new AWS podcast with Certified Expert, Phil Phillips! Listen to "How to Execute a Seamless AWS Migration" on EE or on your favorite podcast platform. Listen Now


problem with 486 PC

witty asked
Medium Priority
Last Modified: 2010-04-26
I've got a problem with two 486 PCs:
A is a AM486DX4 100MHz (ASUS PVI486SP3)
B is a Intel 486DX33 (NONAME Motherboard)

B worked very well a year ago.
Now I wanted to install computer A instead of B
1. I can't access the 3 1/2" Floppy from A (a year ago I installed programs from the floppy!). I changed the floppy cable and used the floppy from B no success.
But the floppies work with B!!!
2. I can't boot from HD from B! I get "Partition table not valid" or a black screen or "Starting Dos ..." and then hang up! I also changed cable and tried the working HD from A. No success. But the HDs work with PC A!
The HD seams to work with B after booting with floppy, but I get I/O errors and hang ups after a while copiing (format works - scandisk yields errors)!

So I have one computer without floppy and one without HD!

Does anyone out there have an idea??

Watch Question

put the working FDD to the computer without FDD
put the working HDD to the comuter without HDD
"Merge" the two PCs into one with FDD and HDD :)
It sounds to me like your floppy/hard disk controllers are on their way out the door. You may need to purchase a new controller card.


It could be misconfiguration in the bios.

1.your floppy controller in A is bad.set your bios to seek floppy
at boot when your computer seeks the a: you should see floppy
drive(s)fail .this will confirm this.
2.this could be a number of things .I seen probs like this when
One bios is in lba mode and the other is not (check your bios).
also If  both Hard drives work fine in A and your floppy
is down so you didn't use a boot disk,then your hard drive should
be fine I would say your hard drive controller is going out!

Witty, this could also be a virus, though I doubt it. You may want to check that. Also check your bios settings as the other experts have stated. You may need to change out your battery, a lot of 486 boards are starting to loose them.

gward28 please do not submit other experts comments as proposed answers, this is purely bad taste.


Tex I logged on before you and potsy stared to answer witty
got company came back finished re connected and submited it .
I'm sorry if had seen it here I would not have submited it as an
sorry again!


ad 1.: At floppy boot seek the floppy is been found, but - you know the sound the floopy makes - sounds a bit "slower" (not aaaaoo but aaaaaaaooooo)!
So I'm not sure if the FD-Controller is bad! My problem is, that I only have got one graphic card (VL) and PC B has an VL I/O CARD and PC A has only one VL-Slot. So i can't test the controller in the other computer (sorry I can, but then I won't see anything)
ad2.: for further explanation:
PC A has an onBoard Controller - and it worked fine for the last 3 years -  I installed a new BIOS and the error occured after that - the HDsettings are correct - even the autodetection works fine. Are there extended settings in the BIOS available, that could work?
And (I think the ASUS-PVI486SP3 is used in many computers!) what do I have to do if I want to use a FD&HD-Controller-Card in the computer with on Board FD & HD-Controller?

Is it possible, that the AM486DX4 100MHz has something to do with this?

(texas: there's no VIRUS)

thanks to all of you

does the card have disable jumpers on it ?you can disable some onboard controllers in your  bois Iv'e seen some that have jumpers.and just not to overlook have you tried both lba modes
(if it has both)0r none in your bios.


I don't have a card yet - I only wanted to know, what to do on the motherboard (when I get one).
Yes, I tried LBA, normal and large - the same result!
Some boards/bios's will also automatically disable the onboard controllers if a new controller card is installed.

The reason the floopy seek sounds longer is because system ram shadow is turned off.  So the BIOS code is executed from the slow PROM, rather than copied to RAM.

On the computer which gives you hard disk partition errors, try perform Auto Detect Hard Disk again just to make sure the computer got the physical dimension parameters right.

It sounds to me like the HD controllers are on their way out,
the slow sound is because it is trying to access the drive as a HDD because it cannot find a primary HDD.

I would suggest trying to auto-detect the HDD's and see what happens.

hope this helps



Thanks to all who helped me!
The Floppy Controller seems to be crxksdö.
But I can now use my other computer as I updated to the newest BIOS Version 306 (there might be some problems with amd486dx4 100).
Now this computer works very fine!!!

Thanks to all of you
I'm going to delete this question in a few days!!

The 486/100 CPUs are VERY bugfree, so the problem is not in the CPU. Try (if you can) re-update (undo/ put your old) BIOS...try with parts (e.g. FDD,HDD, controllers, VGA) from other (not the PC A & B) computers (from your friends, etc..........)


do you know that ASUS's FDD and HDD pin assignment is different from other brands in older dates?  pls ensure you use the original FDD and HDD cable supplied with the motherboard.


I've already solved my problem as you can read above!
but I didn't find a way to delete this question!!


pls find the person gave you the biggest clues and hand him/her the points!!!

they deserve your points for the effort they put in!


You can not delete a question with comments form other experts.
I posted this as answer by mistake. reject - I realy don't have helped you :)


gward28 I think your answers helped me the best.
write a answer, so I can give you the points!
Unlock this solution with a free trial preview.
(No credit card required)
Get Preview


I think that's ok ;-)!

Thank you very much witty .I hope we can be more helpfull next time.
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a free trial preview!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.