Fireing up an old 486

[Cats2001!]

Hey guys - I wonder if you can help me

My brother has lent me his old 486 to 'fix', and says that ever since 2000 came, he could not fire it up. So I turned it on and it would not get past the loading screens. I stuck a Windows 95 startup disk in there, but it would not recognise it (it looked at the 5 inch disk drive!!). So, I opened up the case, and unplugged the 5 inch drive, and pluged in the 3 inch drive to frive A, went to CMOS and re-configured the drives (A: is now the 3inch drive, and B: is now 'none') - and that worked - I could now at least get the startup disk to work and get to DOS.

Thing was - I tried to access C: - but it did not recognise C:!!! So I rebooted and went back to CMOS, and noticed that is had C: = NONE. So, I went through the options. I was looking for 'find C: type automaticle', but that option was not there (it must be an older CMOS operating system), so I went to the highest hard-drive specification there was (213mg or something, even though the HD is over 500 - the closest option that was there was 213 or something!!)

So now I rebooted, and it recognises C: - but it freeses in bootup, saying 'NO OPERATING SYSTEM'.
So I then rebooted with the Startup disk, got to DOS, typed C: (And NOW it worked!!), and I could now access all the files on C:, but when I tried to get into Windows (it happens to be Windows 3.1), it does not go in there - because I have used a WINDOWS 95 startup disk!!!

So a couple of questions:

1) How come the system says 'no operating system' when I boot it - even though there is a version of Windoes theree? Do I need to edit the config.sys or autoexec.com files?

2) I cant rectify getting into windows by using the Windows '95' startup disk (for obvious reasons)

3) Whats the go if I want to install a CD ROM drive? Just say I want to make a D: - I plug the CD ROM in to the circuit board inside the PC - but it does not recognise it. In CMOS - there is no D: option that I can set for a CD ROM drive. Do I need a special 3inch disk that I put into the machine in DOS that will set up the CD ROM drive for me??

Thanks guys

 

[KingyOrTheKing]

First of all, let me say I only have experience with OS's >= win98:

First of all, there may be missing system files. This usually gives the 'insert system disk' at bootup. The easiest thng to do is reinstall the OS, either by CD or if the files are on the Hard drive. You might have to change the jumper settings on the CD drive, since this setting may be conflicting with the physical set up of your IDE cables.
BTW - if you are using a system disk, the CD drive won't be D, but drive E, since D will be taken up by the system disk files in DOS.

 

[trevmartini]

and says that ever since 2000 came, he could not fire it up

That is likely your answer, your bios is not Y2K compliant. You will need to update the bios and this probably won't be easy or cheap.

 

[jim boy]

Originally posted by Cats2001!

1) How come the system says 'no operating system' when I boot it - even though there is a version of Windoes theree? Do I need to edit the config.sys or autoexec.com files?

Although the operating system looks for the autoexec.bat and config.sys, the actual DOS operating system files are command.com, msdos.sys and io.sys. Sometimes these files can get corrupted or misplaced and need to be replaced. But before I tell you how to do that, just a quick question. In the bios, is the hard disk still part of the boot-up sequence? Some bios allow you to not reference the hard disk when starting up. If this is the case, simply fix the setting and your PC should work.

More likely though you'll need to replace the system files. You can't just copy them as they need to be in the first sector of the boot partition. What you need to do is get a DOS bootable diskette with the sys.com tool. Then it's simply a case of booting up via the diskette and typing the command "sys c:" to fix your disk. This will not destroy any data on the hard disk and will preserve Windows 3.1. You want to make sure that you stay with the same version of DOS though as for obvious reasons the Win95 (DOS 7.0) won't work. You can find out which version of DOS you had by finding a DOS file on the hard disk, such as command.com or himem.sys and see what time they where created. They should have been created at something like 6.20 or 6.22. These times are the DOS versions.

If you haven't got or can't get access to creating a DOS bootable diskette, I can send you a disk image of either 6.22 or 6.20 DOS versions, PM me if required. It'll be just under 1MB in size

2) I cant rectify getting into windows by using the Windows '95' startup disk (for obvious reasons)

see above

3) Whats the go if I want to install a CD ROM drive? Just say I want to make a D: - I plug the CD ROM in to the circuit board inside the PC - but it does not recognise it. In CMOS - there is no D: option that I can set for a CD ROM drive. Do I need a special 3inch disk that I put into the machine in DOS that will set up the CD ROM drive for me??

DOS being the old system that it is doesn't recognise CDROMs, you need to find the right driver, load it via the config.sys and start it up with the utility mscdex.exe via the autoexec.bat as per the following example using a BTCCDROM driver.

{config.sys}

DEVICE = a:\BTCCDROM\BTCCDROM.SYS /D:BTCCD001 /V

{autoexec.bat}

a:\dos\MSCDEX.EXE /S /D:BTCCD001 /V

The BTCCDROM driver will pick up most ATAPI compatible cdroms, so it's good to start with this. Again I can provide this driver if necessary.

The other alternative is to boot up with a win95 or 98 install disk. You might have to fiddle about with settings in autoexec.bat or use the F8 button, but these disks try to load a heap of CD drivers and you don't have to use a 95 or 98 disk with them.

As far as year 2000 goes, yeah, you might have a problem. But I am also guessing your brother wont care if the date on the computer is 1992 instead of 2002. That would be the easiest fix. If you really want to fix it, find out the brand and the model number of the board and see what you can find via the internet. Don't hold your breath though.

Hope this helps.

 

[Blue'n'Gold]

In some 486's the cd rom needs to run off the sound card.. .

 

[KingyOrTheKing]

Originally posted by Blue'n'Gold
In some 486's the cd rom needs to run off the sound card.. .

Really?

I know that some CD drives require the sound to be connected to the drive in order to play music CD's...

 

[Blue'n'Gold]

Originally posted by KingyOrTheKing


Really?

I know that some CD drives require the sound to be connected to the drive in order to play music CD's...

I know how strange it sounds, but yeah some do require you to connect the CD Rom to the sound card.. A little while ago I made a forage into the dark ages and rebuilt a 386 and a 486 for no real reason other than i was curious about how they worked. Luckily for me I have a friend who knows a lot more about those than I do, and it was him who pointed me in the right direction with the CD Roms when I couldn't get mine to work