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John
March 17th, 2004, 07:00 AM
I was lucky enough to find a 286 in working order, missing the hard drive only. I used a 486 machine to make a boot disk with some of the basic DOS files on it. What happens is it runs all the way up to where the A:> should show put never gets there. Any advice on what I've done wrong. Thanks in advance! :?

PS.. The boot disk I made will boot the 486 machine.

Erik
March 17th, 2004, 07:17 AM
The first thing that comes to mind for me is memory. Either there isn't enough or you have some bad RAM in the area where DOS wants to load.

The other option is a bad disk drive that isnt' reading the DOS files correctly.

I'm not sure how your machine is configured but if you can swap the floppy drives or banks of RAM then you can hopefully isolate the problem if it's either of those.

Another possiblility that you may not be able to fix or test for is that the BIOS just isn't compatible. A call to a BIOS routine that isn't there or that isn't returning what DOS wants can lock up the machine.

Erik

John
March 17th, 2004, 07:46 AM
Thanks for the reply Eric! How would I tell if the RAM is no good? When the computer is booting it goes through the memory check with out any problems. Screen shows "Starting MS-Dos" and "Himem is testing extended memory..." and then says "OK" the cursor drops down one line and just blinks. This is where the A:> part is supposed to appear. Any additional comments would be helpful.

PS.. I not a tech - I'm a draftmans longing for the computers of my school days.

vic user
March 17th, 2004, 08:55 AM
Hi John;

I am not a MS/DOS expert or anything, but I have sure played around with many versions over the years, and have made tons of different config.sys and autoexec.bat files, I have written up.

Maybe you can use the 486 to open up your config.sys, and edit it, and try and removing the 'DEVICE=C:\DOS\HIMEM.SYS' or its equivalent on your config.sys.

Then try and boot the 286 without memory management, to see if the computer will at least boot up correctly.

Try and keep the config.sys and autoexc.bat files as simple as possible, with just the basics, (and hopefully boots up the computer fine), and then add from there.

Obviously though, you are going to want to use anything past 1 meg of RAM, you will need to run a memory manager.


A good bit of stuff I found:
"286's can use expanded and extended memory but can't handle UMB's (upper memory blocks). You can load DOS high but you can't load any device drivers or TSRs into UMBs (upper memory). To configure extended memory you can load HIMEM.SYS and load DOS high by setting DOS=HIGH but you will have to get a special third party expanded memory manager to configure expanded memory (EMS). The memory manager should come with the expanded memory hardware. The EMM might conflict with HIMEM.SYS, so the HIMEM.SYS might have to be replaced with one that is compatible"

Hope some of this info was helpful.

Chris

Erik
March 17th, 2004, 09:02 AM
Vic user makes a good point. Clean out the autoexec.bat and config.sys files (or rename them completely) to see if the offending items are in there.

If the RAM tests properly on boot then it's probably good although the post check isn't as exhaustive as a full RAM test or actual use.

Good luck!

Erik

John
March 17th, 2004, 09:33 AM
Thanks guys! My autoexec.bat file is already as simple as it can get only containing one line "@echo off", however the config.sys file has a few more lines:

DEVICE=A:\HIMEM.SYS
DOS=HIGH,UMB
DEVICE=A:\EMM386.EXE NOEMS
FILES=30
BUFFERS=20

I'll rewrite it to read:

FILES=30
BUFFERS=20

and see how that goes.
This computer has 2 disk drives A: (3 1/2 " 1.44mb) and B: (5 1/2 " 1.2mb). I would swap these and boot from the 5 1/2 " drive except that My 486 machines 5 1/2 " drive won't format a system disk for some reason (virus problems I think;)). My main concern is that I will be able to run DOS 6.2 on this older machine. I do have DOS Ver3.3 if all else fails. Please keep up the suggestions. I'm sure we can get this old computer up and running!
Thanks again!

vic user
March 17th, 2004, 09:42 AM
John wrote:

DEVICE=A:\HIMEM.SYS
DOS=HIGH,UMB
DEVICE=A:\EMM386.EXE NOEMS
FILES=30
BUFFERS=20
-----

Hi John;

I would just get rid of the "DEVICE=A:\EMM386.EXE NOEMS" statement.

Everything else looks fine.

Chris

John
March 17th, 2004, 09:57 AM
Great! Still boots the 486 system. I can't wait to get home and try it on the 286 system. I'll be sure to post how it turns out. Make sure to check back tomorrow to find out how this all turns out :!:

vic user
March 17th, 2004, 10:13 AM
Oh, and I think you should get rid of ",UMB"

Just pop in:

DOS=high

Since you want DOS loading into high memory, but you do not want DOS to handle the upper memory area.

I have never run DOS 6+ on a 286 before. I have only gone as high as 5.0

Good luck again

Chris

Barry
March 17th, 2004, 11:10 AM
I think I'd boot first with no autoexec.bat or config.sys. That should work if it's a fully compatible computer. Remember that in the early days there were some not so compatible dos computers that had to have special versions of dos.

I think most of the PCs were pretty compatible by the time the 286 came along so that's probably not an issue but it's a possibility.

If it won't boot successfully without a config.sys and autoexec.bat that means it's either got a hardware or compatibility problem.

I remember running into an old XT machine when I only had dos 3.2 and it wouldn't work on it. I got it to work on a copy of dos 2.11 but a lot of things weren't right. I can't recall the brand name now but someone found the special dos for it and it was fine.

You can find websites with bootdisks to download for practically any computer. You get them as an IMZ file and they have pointers to the program that converts that to a disk. Of course you need a computer with a 5.25 floppy to use that. There is a dos version of it.

I don't have a link for one of those websites but I've seen them fairly recently while looking for something else so I know they're still around. A bit of googling should find them.

Barry

John
March 17th, 2004, 11:36 AM
You mean I don't need to have an autoexec or a config.sys file on a boot disk in order to get the computer to load up? Just have my DOS disk in the drive and go? Let me know, I'm interested.
Thanks

Erik
March 17th, 2004, 12:10 PM
You mean I don't need to have an autoexec or a config.sys file on a boot disk in order to get the computer to load up? Just have my DOS disk in the drive and go? Let me know, I'm interested.
Thanks

Correct. Both files are optional.

That used to be my first course of action with DOS problems. Just rename those two files to something else and boot "clean."

Erik

John
March 19th, 2004, 07:47 AM
Success, the disk works (and so does the computer). It looks like the older unit can not run the emm386 program. I also removed the umb reference from the second line. All I need now is a hard drive. Strange though, the hard drive wire leading off the HDD card only has a 32 pin conector. Anyone with any insite please post a reason why. Thanks to all of you for your help with this.

Super-Slasher
March 19th, 2004, 09:54 AM
32-pin instantly reminds me of MFM interfaced hard disks. MFM required two ribbon connectors for hard disks, a 32-pin and a 20-pin if I recall correctly.

Perhaps you can give more info on your controller card?

John
March 19th, 2004, 10:04 AM
I'll try to post a picture of it tomarrow (Saturday) night. It won't knock your socks off but... it will make it clearer what we're talking about. Only the HDD/FDD board has pins the other end of the cables have a slot connector. I pulled a hard drive out of a 486 machine but couldn't use it because it has pins on the back of the HD.

barryp
March 19th, 2004, 01:32 PM
Strange though, the hard drive wire leading off the HDD card only has a 32 pin conector.

Are you sure it's not 34 pins? (That would make it MFM or RLL or ESDI or...)

32 pins would just be strange.

Super-Slasher
March 19th, 2004, 02:04 PM
Yup. Sounds like MFM to me.

Terry Yager
March 19th, 2004, 07:07 PM
Success, the disk works (and so does the computer). It looks like the older unit can not run the emm386 program. I also removed the umb reference from the second line. All I need now is a hard drive. Strange though, the hard drive wire leading off the HDD card only has a 32 pin conector. Anyone with any insite please post a reason why. Thanks to all of you for your help with this.

When you say 32-pin connector, do you mean it's actually a 34-pin connector with a coupla pins missing or cut off? Also, check to see if there is a second, 20-pin connector present. While this still won't tell us the exact type of drive, (MFM, RLL, ESDI) it'll help narrow it down. If you can find a name/model # on the controller board mebbe someone can look it up for ya.

--T

John
March 22nd, 2004, 07:35 AM
Your right Terry! It is a 34 pin and it does have a second connection, most likely a 20 pin. I pulled an old seagate HD out of another computer that I had laying around and I'm trying to get it to work. The only problem is I can't remember how (which direction) the cable attached to the HDD board. I guess I have a 50/50 chance on getting it right.

barryp
March 22nd, 2004, 03:51 PM
I guess I have a 50/50 chance on getting it right.

Look on the board for a tiny 1 (or 34, or both) next to the header, the stripe on the ribbon cable goes on the pin 1 end. On the drive end, there's a key cut in the circuit board, that's nearest the pin 1 (stripe) end. AND, be sure the drive itself is set to the first position if it's to be the C: drive.

Terry Yager
March 22nd, 2004, 04:00 PM
Your right Terry! It is a 34 pin and it does have a second connection, most likely a 20 pin. I pulled an old seagate HD out of another computer that I had laying around and I'm trying to get it to work. The only problem is I can't remember how (which direction) the cable attached to the HDD board. I guess I have a 50/50 chance on getting it right.

If the designer had any class at all, the cable will be keyed in some way to prevent mishap. OTOH, if it is not keyed, then look closely at the cable and it's connectors, both on the card and on the drive. The cables should have a red line along one side of them. That will indicate pin #1 on the cable. Now, looking at the controller card and there should be some kind of marking near the connector (usually a 1, next to pin #1). Match up the red stripe to the #1 pin, then do the same at the drive end. If that is not marked, most drives (but not all) have pin #1 farthest away from the power connector.
The best thing to do, with those old drives, is to swap-out the controller board along with the drive, to avoid any formatting problems or incompatability between the drive and controller. (That way, you don't even have to disconnect the cables, so you won't get confused which way they go back on). Good luck, hope this helps...

--T

John
March 23rd, 2004, 07:53 AM
To late, I have already pulled the cables off (hence may dilema). Do you think that the HDD controll board is marked in some to identify the first pin? Keep in mind - the cables are removed from HDD board and hard drive. The one end has a key like you mentioned. I'll have to take a real close look at the board tonight.

barryp
March 23rd, 2004, 08:14 PM
To late, I have already pulled the cables off

In most (All?) cases, the pin ones are consistent; all left or right, including the floppy...

mbbrutman
March 24th, 2004, 01:14 PM
Be careful. ESDI and MFM share the same cabling, but they are not compatible.

Terry Yager
March 24th, 2004, 03:06 PM
Be careful. ESDI and MFM share the same cabling, but they are not compatible.

OTOH, RLL and MFM drives are sort of compatable. RLL drives can be formatted to MFM, but not the other way round.

BTW, if the board does not have a numeral 1 screened on it, there's still a chance to identify pin #1. Look at the reverse side (solder side) of the board, at the back of the drive header. Most of the time the solder pad for pin #1 is square, while all the other pads are round. (This doesn't always apply, YMMV).

--T

barryp
March 24th, 2004, 06:03 PM
Be careful. ESDI and MFM share the same cabling, but they are not compatible.

But connectong an ESDI drive to an MFM controller won't be fatal.

I once sold a 286 with an ESDI drive to a semi-knowledgable friend. I wasn't around when he wanted to upgrade so he took it to a local shop. They tried all sorts of combinations to put two drives in the same box. The moron in the shop insisted that the ESDI drive was dead, although he didn't know it was ESDI.

When I returned I was quickly able to transfer his software to the new drive using a null-modem cable between two computers.

barryp
March 24th, 2004, 06:07 PM
OTOH, RLL and MFM drives are sort of compatable. RLL drives can be formatted to MFM, but not the other way round.

I've been able to convert an RLL drive back to MFM. It took several low-level formats but it worked.

Is my memory correct that there were different RLL formats? Aren't there 25 and 26 SPT formats?

Terry Yager
March 24th, 2004, 07:28 PM
OTOH, RLL and MFM drives are sort of compatable. RLL drives can be formatted to MFM, but not the other way round.

I've been able to convert an RLL drive back to MFM. It took several low-level formats but it worked.

Oh, that's easy... The hard thing to do is go back to RLL after using the drive as MFM.


Is my memory correct that there were different RLL formats? Aren't there 25 and 26 SPT formats?

Well, yes...and no. MFM (modified frequency modulation) and RLL (run length limited) are both methods of encoding data for storage on some medium, usually a magnetic disk. They have nothing to do with the actual formatting of the medium, even tho we commonly speak of "MFM format", etc. (IBM format 5.25" floppy disks use MFM encoding, but are only 8 or 9 sectors:track). The yes portion of my response has to do with whether or not you are speaking of strictly MSDOS-type computers. In the world of MSDOS, RLL drives are usually (always?) formatted with 26 S:T, and MFM drives are 17 S:T. However, different OSs may format either kind of disk any way they want to (within the phisical limitations of the hardware). So yes, RLL (& MFM) can be other than 26 sectors, but not usually under DOS.

ESDI, OTOH (even tho you didn't ask), is neither a formatting standard or an encoding method. ESDI (enhanced small device interface) refers to the electrical interface (hardware) that controls the device (via software). Other interfaces include the ST506 interface that MFM and RLL drives usually attach to, as well as others (SCSI f'rinstance).

--T

carlsson
March 25th, 2004, 02:51 AM
Hmm.. I have a vague memory of once managing to kill a hard drive in college where we had a few 286 systems with different interfaces. Back then, none of us had the knowledge what is what, and it ended up in bad smell and maybe even a puff of smoke. I can't remember if it was due to connecting the wrong type of drive to the wrong interface or because the BIOS was set with wrong parameters. :oops:

Oh well, that is more than ten years ago, and those machines most probably have been "recycled twice" since then.

Terry Yager
March 25th, 2004, 04:16 AM
Hmm.. I have a vague memory of once managing to kill a hard drive in college where we had a few 286 systems with different interfaces. Back then, none of us had the knowledge what is what, and it ended up in bad smell and maybe even a puff of smoke. I can't remember if it was due to connecting the wrong type of drive to the wrong interface or because the BIOS was set with wrong parameters. :oops:

Oh well, that is more than ten years ago, and those machines most probably have been "recycled twice" since then.

More likely, the drive was plugged in backwards. (My memories of such incidents are anything but vague). Once, I killed the 10Mb (MFM) drive & the controller in my Tandy 1000HD by connecting the data and/or control cable backwards. Another time, I did in a 2Gb (full-height) SCSI drive by plugging the SCSI cable in backwards (that one went out with a bad smell, a puff of smoke, a loud noise and flash of light). I killed a Celeron 333 mobo once by plugging the power cable to the CD in up-side-down (I was working "blind", by feel). The plug went in easily, so I figgered it was ok, till I turned on the machine. Another mishap was when I plugged in the power connector to a 3.5" floppy drive up-side-down. That one only took out the floppy controller, which was built in to the mobo. That computer is still on the job today, minus any floppy (I gave it to my nephew).

Connecting the drive to the wrong kind of interface (with similar cableing) is not likely to do it any harm, it just won't work. Neither should setting the wrong parameters in the bios setup.

--T

Jorg
March 25th, 2004, 10:07 AM
It looks like the older unit can not run the emm386 program.

Well it does say emm386 doesn't it ;)

carlsson
March 25th, 2004, 02:46 PM
I killed a Celeron 333 mobo once by plugging the power cable to the CD in up-side-down
Normally these cables only fits one way, at least on European systems, or the connector was very worn. I once killed a motherboard by assuming the fan power connector was a jumper block and short circuited some 12V upon booting.

I believe that we (or I rather) actually by accident or curiosity changed the BIOS settings from user defined disk to one of the fixed ones, and the drive really didn't like to be accessed with the wrong assumptions about heads, cylinders etc. Or maybe the user defined settings were lost and it could be read off the disk label.

John
April 12th, 2004, 09:29 AM
Ok I have the hard drive connected to the controller card in the proper order (pin one to pin one...). CMOS will allow me to run diagnostics on the dive which seam to be telling that every sector on the disk is bad. When I got this HD I was asured that it was working. Would anyone be willing to list out - step by step - the procedure for getting a drive up and running on a 286 machine. Please.
PS .. I have tried DEBUG, FDISK, and FORMAT ... The guy I got the drive from said I sould try a low level format?? I haven't been able to find out much about how I would do that, although at www.computerhope.com they did mention the word but not much more.
I used DEBUG to erase all disk partitons.... Seemed to work as expected.
FDISK because the DOS manual said that you had to... Just get errors.
And FORMAT c:/s because thats what I thought you should do.... Invalid drive error.
The HD is a Seagate ST251 if it maters and I selected drive type #40 in CMOS setup for it.

Terry Yager
April 12th, 2004, 11:54 AM
Usually, when you get errors on every sector it's because the drive geometry is set wrong in the CMOS. For an ST-251, the geometry should be (IIRC) 6 heads, 820 cylinders, 17 spt for a total of 42Mb (look it up at Seagate's website, just to be sure). To low-level format it there are two different (common) ways, depending on your machine's BIOS. Either there will be a formatting program in your machine's CMOS setup, or you'll have to find a LL format program that runs from disk. (A web search should turn up a few). After the LL format, then you'll have to run FDISK to partition the drive. Depending on which version of DOS, you may not be able to use the whole drive as a single partition. (Versions before 3.31 were limited to 32Mb for a partition's maximum size). After setting up the partition(s) with FDISK, then rebooting the machine, then you run DOS's FORMAT to high-level format the drive, then install the OS and you're there.

--T

Terry Yager
April 12th, 2004, 12:06 PM
John,

Configuration info here (with pictures):

http://www.seagate.com/support/disc/mfm/st251.html

General formatting info here:

http://www.pcguide.com/ref/hdd/geom/formatUtilities-c.html

--T

John
April 13th, 2004, 06:11 AM
Ok, I down loaded a LLF program from a site. When I ran the program it had an error on every track. It (the program) had a write/verify option which I chose. This is what generated the error message - VERIFY ERROR ID - or something like that, however the format option seamed to work fine. I believe that I have the drive connected correctly. The drive is connected to J2 (34 pin) and J3 (20 pin?) on the controller card. I don't know what else there could be with the execption that the drive is trashed. Any have any good suggestions on how to resolve this problem?