How can I get my 486 to recognise my CD-ROM drive?

[cryptotooth]

the other day I was given a 486 computer running IBM dos 5.0 and win 3.1, 106MB hard drive etc. But I'm having a problem getting it to recognize my CD-ROM drive from 1998. I had it working by configuring the drive parameters in the very old BIOS and turning it to a "type 48" drive. Then had it working with my DOS boot floppy with oak CD driver, but I unplugged the drive and configured the BIOS for my 1gb hard drive (didn't work anyway) and put the CD drive back in and now no matter what I do, it always says "fixed disk configuration error" and won't boot from or detect the drive. what can I do to get the drive to work again? It boots of the hard drive with this error so I'm sure it's to do with the CD drive.
the type 48 drive options I currently have are "cyl: 0 Hd:1 pre: -1 LZ: 0 sectors: 10 size 0"
These are what I have from messing around with it to try and get it to work again. before they were changed I was browsing a win98 setup disk fine, but now I always get this error. can someone give me the correct settings for my BIOS to get this thing to work with the 106 MB drive, or possibly even the 1GB drive and the CD-ROM? I think I just need these parameters set again (assuming they are actually parameters) and it should work. I tried loading the default values for all options but it still doesn't work . could someone give me what these settings should be?

thanks in advance.

 

[Saberus]

Some points to check:

make sure the CD drive is still jumpered correctly for it's position on the IDE ribbon cable. At the very end of the cable? Should be Master, in the middle/2/3rds position? Jumper for Slave. CS/Cable Select should be avoided, as I doubt the motherboard is able to handle that.

In the BIOS set the position the CDROM is installed at to Auto or CDROM or none.

To get the drive to work as well, jumper it properly for it's space on the cable as above and try Auto in the BIOS. If Auto fails, the drive should have its CHS settings printed on the label, you can input that manually.

 

[mbarnes86]

Hi

I dont think this old PC is worth playing with except as a museaum piece
(and then only if a IBM or Compaq or some other well known brand

i486 from 1989 to early 90's and replaced by Pentium (1) in 1993/5


Bios this old may not support auto detection of the hard drives and only select a drive with data previously entered into a table in BIOS

Or you need to know the number of tracks, sectors per track, number of heads
and pre value (can't remember what this is)
LZ = landing zone track

You may be able to Google this information for this drive if not on a label

tracks x sectors per track x heads x 512 = size of hard disk in bytes

cylinder similar to tracks

regards
Mike Barnes

 

[fzabkar]

Your optical drive doesn't need to appear in BIOS. In fact early 486 BIOSes only supported HDDs. Set the CDROM's drive type to None.

You need to include your Oak driver in CONFIG.SYS, and MSCDEX.EXE in AUTOEXEC.BAT.

You won't actually be able to boot from the CD. Instead boot from your floppy diskette, then run the SETUP.EXE file on your Win98 CD.

 

[cryptotooth]

The CD drive is set to slave, and the hdd should be master as it works on the master channel and is disk 1 in the bios. and the bios must be old cause there's no option to set it to CD-rom, but it did work originally with type 48 drive, but then like I said, I changed the settings and it won't pick it up anymore. I tried a new ribbon cable and still nothing. the hard drive works in it and boots into dos fine, but still, I can't get it to work with the OAK cd-rom drivers I downloaded with the image from bootdisk.com ages ago which came with the boot disk. Basically I just need to know what I should set the sectors, heads, tracks, landing zones etc to to get it to work again. I can't fully take out the battery but it only seems to power the real time clock anyway, and I can't find any jumpers to reset the bios. going into setup and reloading defaults doesn't help either. I'll try another drive now although I highly doubt it'll work.
there's also only one IDE channel on the board so I have 2 drives on a single cable.

I've just left school and I'm really into computers new and old, and have 2 months to kill, so I think this machine would be a great project alongside building my new i7 machine. what if I got an old ISA sound card? would that work with the IDE channels on there, although I might need to set interrupts up and stuff.

 

[Saberus]

The IDE channel on a ISA sound card is hit and miss in my experience. Some might let you use the CDROM as a data drive, while others only permit it to function as a music player straight to the audio. This was useful in freeing the processor from having to address the CDROM when it wasn't doing anything but playing audio CDs. Either way, the ISA bus is 8/16 bit at 8.3MHz, the drive will run painfully slow transferring data if it's presented to the system as a data drive.

 

[mbarnes86]

Hi

Something I should have said earlier
post motherboard make & model
i486 speed (for Win 98 minimum 486DX 66 megahertz recomended)

If you Google on make & model you may find the motherboard manual/user guide
If no longer available try the Internet archive/way back machine or a computer museum web site

There are a number of MS DOS CD Rom drivers available depending on chipset.
Try and find a Windows 95 boot floppy disk, a freedos boot floppy disk or something similar with a collection of CD Rom drivers to find one which works (put them all in config.sys)

How much ram does your 486 have ?
is there enough for Windows 95 ? (8 Meg or 16 MB)
or Windows 98 ? (24 or 32MB)

regards
Mike Barnes

 

[cryptotooth]

Thanks for the info. turns out, after a long time trying to remember the type 48 drive config I finally got it, and the hard drive was set to master with no other drives on it's jumper settings. After looking the drive online I managed to get it to work and everything runs fine although it does still say fixed disk configuration error. no idea why.
I'm not sure of the specs, but I think it's an i486sx @25mhz (such a powerhouse) with 4mb simm ram (was gonna upgrade it to 16/32. After looking it up, people say it will be unbearably slow on these specs with 95, and it's not fast with 3.1. Now all I need is an isa ethernet card and a sound blaster.
Also while we're all here, does anyone know how to change the wallpaper in win3.1? the last owner set it to an ugly white and blue.
If I was to order another CPU online, preferably faster than 30mhz, would it work alongside or take over from the current one, or not work at all? would it have to be intel? will a dx2 work? there's a socket on the motherboard so it makes sense that it would work.

 

[Saberus]

That second socket is meant for the 487 math co-processor. If you stick a 486 in there it likely won't fit, and definitely won't work.

 

[mbarnes86]

Hi

It will be very hard to find a upgraded CPU for a i486DX socket cpu
The 486sx was a faulty 486DX where the maths co processor had failed to pass the tests and was disabled
the 486DX was the first intel cpu to include the maths co-processor in one chip instead of an add on chip costing almost as much as the original cpu

[maths co processor was a worth while upgrade to speedup Lotus 123]

the i487 was effectively a fully working i486DX with slighlty different pin/socket

I upgraded my i486DX with an P24T pentium overdrive upgrade chip (25MHz x3 = 75MHx) (1994/5)

for details of what 486 models exist
http://en.wikipedia.org/wiki/Intel_80486

you will need the motherboard manual to see what models are compatible as some require 3.3V others 5.0V

(unfortunately I recently threw out a few ISA cards (ethernet , sound, video etc and a few old cpus)

has anyone got any spare ISA cards in there junk box ?

regards

Mike Barnes

 

[fzabkar]

What BIOS ID is reported during the POST?

 

[cryptotooth]

fixed the bios errors. the last guy set the graphics config wrong. I set it to ega/vga and it works fine. the fixed disk error randomly disappeared too.
This CPU is soldered to the motherboard so I thought that the other socket would be a good idea for an upgrade. even if it is just for a math co chip, would there be any performance increase?

 

[cryptotooth]

Or will a single board computer fit into the ISA slots? I know it'll be slow as hell.

 

[mbarnes86]

Hi

as I said previously a 80487 is a 80486 so cpu + maths co processor

http://en.wikipedia.org/wiki/X87

80487

The i487SX was marketed as a floating point unit coprocessor for Intel i486SX machines. It actually contained a full-blown i486DX implementation. When installed into an i486SX system, the i487 disabled the main CPU and took over all CPU operations. Although Intel took measures to require the presence of an i486SX for i487SX to function properly, Intel admits that some systems can function with i486SX absent. Intel however cautions that such configuration is not guaranteed to function properly


If you use large lotus 123 or excel spreadsheets the maths co precessors helps

If the clock speed is faster than existing 25MHz say 50 or 66 or 75 or 100 Mhz then yes

regards
Mike Barnes

 

[cryptotooth]

95 is now running, but slow as hell. I'd still upgrade the ram at some point. So, I didn't fully understand the reply to me asking if I could upgrade the processor. If I installed the new one next to it, would it take over from the one soldered to the board? work with it? or will it not fit at all. 'd upload a picture of the socket but it doesn't want me to.
I'd buy this if it will work, it is AMD so probably not: http://www.ebay.co.uk/itm/AMD-486-DX2-80-CPU-Processor-Complete-with-Heatsink-and-Fan-/181418932699?pt=UK_Computing_CPUs_Processors&hash=item2a3d6939db
and this if it has to be intel, although it is a pentium: http://www.ebay.co.uk/itm/Intel-PODP5V-Pentium-Overdrive-Processor-SU014-CPU-486-83Mhz-RARE-Vintage-Genuin-/201051325254?pt=CPUs&hash=item2ecf97c346
and this, as it is a intel 486 chip: http://www.ebay.co.uk/itm/A80486DX2-66-Intel-SX955-486DX-80486DX-80486-486-DX2-66MHz-Processor-CPU-/251532999306?pt=CPUs&hash=item3a9088fa8a

will any of these work? I'd like to speed this thing up a bit. Will the AMD work with the intel? Will the pentium work?
will any work? or am I stuck withh the 25mhz snail?

 

[mbarnes86]

Hi

With a i486sx soldered to motherboard only a i487 can be used or fit in 487 socket
It will switch the i486sx off and provide CPU + maths co processor

How much faster depends on speed of 487

Extra ram will be more important to improve performance of win 95

Regards
Mike Barnes

 

[cryptotooth]

so basically, If I was to buy the intel 486 listed above, I'd still be using a 25mhz chip, but with the other socket using a 487 as a math processor, speeding it up slightly Am I right? does 487 just mean that it's a 486 working with another 486?
oh, I think I get it now. it's a different chip that provides the additional functionality. Where can I get one of these chips? I looked on ebay briefly and found nothing.