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Mystery
October 15th, 2013, 10:41 AM
Hi everybody!

I recently dug up my old 8088 computer and discovered it has stopped working. While looking for a solution, I've come across this forum.
The last time I had it powered on was a couple of years ago and I played Civilization on it. Good times.

It's an 8088 with an NEC D8088D-2 CPU and a 8087 coprocessor. 640K RAM installed.
A cheap "CHIPS" 8-Bit VGA card, two floppy drives and two MFM drives formatted to RLL on the WD1002-27X controller.
The mainboard is a noname "10MHz Turbo Board".

The system has been working fine for over 20 years, but now I'm getting an error message when booting it up: "ROM BASIC ERROR. SYSTEM HALTED." After the bios checks the RAM, keyboard and other stuff.

I *think* I've narrowed it down to the WD1002-27X controller, but of course I'm not sure. If I remove it or set the W3 Jumper (Bios enabled/disabled) to "open" (disabling the bios), I don't get any error message...and no access to the HDDs.


Is the controller broken? Or have I messed something up? It's been ages since I've worked with the hardware, so I'm quite rusty when it comes to configuring and troubleshooting this machine. Everything should be configured correctly, I haven't changed any other jumper settings and they have worked for the last 20 years. I only experimented with the HDD controller's bios jumper.

Alright, that's it for now. If you need any additional info, just let me know. Hopefully I can get this system up and running again :)

Stone
October 15th, 2013, 11:09 AM
An excellent little controller. I have several of them, even an extra if anybody needs one.

Here's the specs so you can check if you've got everything set just right:

http://stason.org/TULARC/pc/hard-disk-floppy-controllers/U-Z/WESTERN-DIGITAL-CORPORATION-Two-RLL-ST506-412-driv-219.html

modem7
October 15th, 2013, 10:54 PM
"ROM BASIC ERROR. SYSTEM HALTED."
AS soon as I read that, I thought to myself, "The contents of one or more of the BASIC ROMs on the motherboard have become corrupt", but ...


I *think* I've narrowed it down to the WD1002-27X controller, but of course I'm not sure. If I remove it or set the W3 Jumper (Bios enabled/disabled) to "open" (disabling the bios), I don't get any error message...and no access to the HDDs.
That suggests that the ROM on the WD1002-27X is what has become corrupted. What happens normally during motherboard initialisation is that the motherboard will discover the ROM in the WD1002-27X and before executing the code in it, verify that the checksum of the ROM is as it should be.
If the checksum is not as expected, then what happens depends on the make/model of motherboard. For example, in an IBM XT, if the corrupt ROM is at address C8000, then what is displayed on-screen is "C8000 ROM". Maybe there is a bug in your motherboard's BIOS that results in the "ROM BASIC ERROR" error for all cases of corrupted ROMs.

Anyhow, on the assumption that the problem cause is in fact the WD1002-27X ROM:

Rather than the ROM in the WD1002-27X actually being corrupt, there could be a poor connection somewhere. First, try reseating the ROM in its socket (wiggle the ROM in its socket).

Next remove/insert the WD1002-27X card a few times. There have been members of these forums who found that that was not enough, and that they had to clean the edge connector on the card.

Mystery
October 16th, 2013, 09:42 AM
Thanks for the tips so far.

The jumper settings are correct, I checked them but found nothing out of the ordinary.

Unfortunately the ROM isn't socketed so replacing or reseating it would become a little bit bothersome.
I've tried the card in different slots and cleaned it, although it wasn't particularly dirty or used. The edge connector is really clean and the card hasn't been used much.

Looks like I've got to start looking for a replacement.

vwestlife
October 16th, 2013, 02:25 PM
The system has been working fine for over 20 years, but now I'm getting an error message when booting it up: "ROM BASIC ERROR. SYSTEM HALTED." After the bios checks the RAM, keyboard and other stuff.

Are you sure it doesn't say "NO ROM BASIC, SYSTEM HALTED"? That's the message you can sometimes get if the computer tries to boot from a hard drive that doesn't have any operating system installed on it. That issues the INT 18h "boot failure" command, which causes the computer to look for ROM BASIC as a last resort of having something to boot into (after it already tried the floppy drive and hard drive), and if there's no ROM BASIC (as on any non-IBM machine), you'll see that error message.

If you see that error, it's actually a good sign, because it means the computer recognizes the hard drive, but isn't finding any operating system on it. The solution is to boot from a floppy disk, then run FDISK to partition the hard drive (and don't forget to make the C: partition "active"), and then FORMAT C: /S to format the hard drive and make it bootable.

RWallmow
October 16th, 2013, 02:42 PM
Are you sure it doesn't say "NO ROM BASIC, SYSTEM HALTED"? That's the message you can sometimes get if the computer tries to boot from a hard drive that doesn't have any operating system installed on it. That issues the INT 18h "boot failure" command, which causes the computer to look for ROM BASIC as a last resort of having something to boot into (after it already tried the floppy drive and hard drive), and if there's no ROM BASIC (as on any non-IBM machine), you'll see that error message.

If you see that error, it's actually a good sign, because it means the computer recognizes the hard drive, but isn't finding any operating system on it. The solution is to boot from a floppy disk, then run FDISK to partition the hard drive (and don't forget to make the C: partition "active"), and then FORMAT C: /S to format the hard drive and make it bootable.

It could also be that the controller is not detecting any hard drive and passing INT 18h boot failure....

Either way, boot disk time to see if fdisk even sees a hard drive.

Mystery
October 17th, 2013, 05:02 AM
Alright, it seems like there's something else, beacue I'm encountering some strange errors.

To confirm vwestlife's question: The error does definitely say "ROM BASIC ERROR SYSTEM HALTED" with a line break after "ERROR" and in a different font/resolution than the regular text output.

I get the same error when I don't connect any harddisks, so it can't be that they are being properly detected.


Now here's the fun part: The system won't boot from floppy disk. It'll complain if there's no disk inserted, the drives are being detected when booting up and when I insert a boot disc, it starts reading is (motor moves once) but then it just stops with the access light still on.

I've tried two floppy drives and two boot disks so far. I'll check the boot disks on another computer and maybe create a new one, just to be sure.

So it seems like theres another issue. One strange thing is, the system won't post properly unless I hit reset after flipping the power switch.
I guess I'll take the whole thing apart, clean everything and check all settings, jumpers, cards etc. and report back here.

Edit: My previous reply seems to have been lost.
Stone: All jumper settings on the controller are correct.
modem7: The rom chip is unfortunately not socketed, so replacing/reseating it would take some work. The controller is clean, the contacts aren't worn out and I've tried multiple different slots on the mainboard, all without luck.

modem7
October 17th, 2013, 08:14 PM
The rom chip is unfortunately not socketed, so replacing/reseating it would take some work.
Disregard my suggestion - I had incorrectly assumed that the ROM is socketed, based on the fact that the ROM on my WD1002-27X is socketed (photo (http://www.minuszerodegrees.net/rom/WD1002-27X.jpg)).


I've tried two floppy drives and two boot disks so far. I'll check the boot disks on another computer and maybe create a new one, just to be sure.
That is a good idea. I presume that you are writing of 360K drives and floppies.

modem7
October 18th, 2013, 01:07 AM
To confirm vwestlife's question: The error does definitely say "ROM BASIC ERROR SYSTEM HALTED" with a line break after "ERROR" and in a different font/resolution than the regular text output.
So if there is no floppy or hard drive to boot from, perhaps the POST/BIOS attempts to jump to BASIC. Maybe there are no BASIC ROMs on your motherboard, and because (without effort), the POST/BIOS can not tell the difference between no BASIC ROMs and corrupt BASIC ROMs, it simply issues a generic BASIC error ("ROM BASIC ERROR").

That sounded plausable until I remembered that you do not see the "ROM BASIC ERROR" with the WD1002-27X removed (or its BIOS disabled). Had it been the other way (BASIC error with the WD1002-27X removed), things would have started to make sense to me.


So it seems like theres another issue. One strange thing is, the system won't post properly unless I hit reset after flipping the power switch.
Do you have another power supply that you can try?

Mystery
October 18th, 2013, 01:54 AM
The board does not have a BASIC ROM, the socket is empty. It might be that the faulty controller for some weird reason causes the system to try to load the basic rom, but I have no idea how or why. But the cause of the problem is most likely not the missing basic rom, but the defective bios rom of the hdd controller.

The power supply is probably on its last leg, but it seems to be stable after it's turned on for a while. I might try changing it, although I'd have to open it up and switch the insides with another unit, because it's not a standard AT form factor and I really want to keep the desktop case which it's made for.

On the bright side, I've finally gotten the damn thing to boot off a floppy disk. It seems that most of my old 720KB DD 3.5" disks have died and finding a working one did take some time. Or the drive needs some serious cleaning. But at least that's one concern less and I can focus on the HDD controller again.

I'll check if fdisk finds anything as soon as I get to it. Trying to make it boot from floppy took way too long.

Stone
October 18th, 2013, 03:55 AM
Disregard my suggestion - I had incorrectly assumed that the ROM is socketed, based on the fact that the ROM on my WD1002-27X is socketed (photo (http://www.minuszerodegrees.net/rom/WD1002-27X.jpg)).I have five of these controllers and none of them has a socketed ROM. :-)


The board does not have a BASIC ROM, the socket is empty. It might be that the faulty controller for some weird reason causes the system to try to load the basic rom, but I have no idea how or why. But the cause of the problem is most likely not the missing basic rom, but the defective bios rom of the hdd controller.So disable the BIOS on the card and see if that helps. It's easy enough.:-)

modem7
October 18th, 2013, 12:46 PM
I have five of these controllers and none of them has a socketed ROM. :-)
Excellent. When I put mine on eBay, I'll be sure to use the words, SUPER RARE. :)

Mystery
October 18th, 2013, 10:41 PM
So disable the BIOS on the card and see if that helps. It's easy enough.:-)
Disabling the bios on the controller will remove the error, but I also won't have access to the harddisks anymore.
FDISK doesn't find any fixed drives when booting from floppy with the controller bios disabled.
Of course, with the bios enabled, I don't get to boot from floppy because the error message halts the system ;)

modem7
October 19th, 2013, 12:40 AM
I brought out my WD1002-27X card, and my IBM 5160 that has no hard drive.
Into the 5160, I plugged in the WD1002-27X (with no hard drive attached) and then powered the 5160 on.
The RAM count went up to 640K, then after about 45 seconds of 'nothing', the BIOS in the WD1002-27X displayed the typical "1701" generic error.
The WD1002-27X BIOS then handed control back to the motherboard POST and the POST went on to display the standard F1 key message.
That was what I expected.

I see that the BIOS sits at C800:0
You could possibly verify that by disabling the WD1002-27X's BIOS, then booting from DOS diskette, then enabling the BIOS, and then using DEBUG per below.

http://www.minuszerodegrees.net/images3/WD1002-27X_debug.jpg

Mystery
October 19th, 2013, 01:35 AM
Just gave it a shot. I get the 1701 message as well, when the HDDs are not/incorrectly connected.

I booted with the bios disabled, reenabled it and went into debug. Here's the result:
http://i.imgur.com/mNAzu0X.jpg
I can't really tell if there's anything wrong with that.

Mystery
October 19th, 2013, 01:38 AM
http://i.imgur.com/mNAzu0X.jpg
Here's the result.
I also get the 1701 error when the HDDs are not/incorrectly connected to the controller.

I can't tell from the debug content if there's anything wrong with the bios. But it seems like there's some functionality left, judging from the 1701 message and the partial (C) info in the debug text.

Stone
October 19th, 2013, 04:03 AM
Well, if you want a replacement card you know I've got an extra.

Mystery
October 19th, 2013, 06:32 AM
I think I'm slowly getting somewhere, and it might be a defective HDD and not the controller, but I'm not 100% sure yet.

I've connected a different PSU and as suspected, the computer started right up instead of me having to push reset. So I'll need to transplant the innards from the new psu into the old one.

After some fiddling around, I got the -secondary- drive to actually work. Now, it doesn't boot up, because there's no OS on it, but if I boot from floppy, I can access the drive and data, which indicates to me, that the controller might be working after all.
Okay, but the problem is, that I still can't access the primary drive, with the OS and additional data. After swapping some cables, I've been able to get a "Error accessing fixed disk" instead of the "No fixed disks found" (or something like that) error message fdisk usually throws at me. Fdisk works fine with the secondary disk.

So the "basic rom" error message might actually be referring to the missing basic rom chip on the board, due to the system not being able to boot from HDD.


The drive in question is a Micropolis 1325 69MB, ST506 MFM, 5.25" full height drive. It spins up, but I'm not able to access it by any means.

Now, I'm a little bit hazy when it comes to hooking these drives up, but if memory serves correctly, I'm supposed to connect the primary drive to the end of the twisted cable and the secondary in the middle.

I'm not really sure where to go from here in terms of troubleshooting the primary disk drive.

Mystery
October 21st, 2013, 02:01 AM
I'm getting a little bit hesitant to reply to this topic, because I've made several posts with further tests/discoveries/explanations in the last couple of days which are still awaiting moderation. Sometimes a posting is displayed immediately, and sometimes it's held for moderation.

Anyways, here's a short summary:
-tried checking the bios via debug, as suggestes, and it seemed fine. I've supplied a screenshot in one of my not-yet-approved posts
-after some fiddling with the wiring and bootdisks, I've been able to access the secondary hdd and make it bootable which led me to believe that the controller is actually fine and the culprit is the primary hdd
-the primary hdd is a micropolis 1325. It spins up, heads don't move and sometimes it spins down and back up again. Turns out it's a common error of that model and fixing it seems rather difficult

modem7
October 21st, 2013, 03:14 AM
Yes, sounds like the hard drive.
What is interesting to me is that, with no disks connected to the controller, you see "ROM BASIC ERROR SYSTEM HALTED", and I see "1701". Odd.

Stone
October 21st, 2013, 04:28 AM
-after some fiddling with the wiring and bootdisks, I've been able to access the secondary hdd and make it bootable which led me to believe that the controller is actually fine and the culprit is the primary hdd
-the primary hdd is a micropolis 1325. It spins up, heads don't move and sometimes it spins down and back up again. Turns out it's a common error of that model and fixing it seems rather difficultYes, I've got a few of them that do that. They're probably just good for parts now -- the parts that still work correctly, that is. :-)

Mystery
October 21st, 2013, 05:42 AM
Well, I'm still glad the controller and the other hdd are alright. Still, too bad about the lost data on the micropolis hdd.

modem7: I get an 1701 error as well, the basic rom error comes after that.


I guess I'll build an IDE controller for the system next. Working MFM/RLL discs are somewhat hard/expensive to come by.

Stone
October 21st, 2013, 05:54 AM
I've also got a Seagate ST-238R in excellent condition if you're interested in that.

MikeS
October 21st, 2013, 08:29 AM
It spins up, heads don't move and sometimes it spins down and back up again. Turns out it's a common error of that model and fixing it seems rather difficultSounds like the common Micropolis sticky bumper problem all right, but not that difficult and definitely worth while if you have data to rescue.

Lots of info out there; google 'micropolis sticking heads'

Stone
October 21st, 2013, 11:23 AM
I've got a couple of these and neither is the sticky bumper problem. One spins up, the heads move to track 0 and that's it. The other spins up but the heads don't move at all. If you try to move them even just a wee bit the drive shuts down. And if you don't fool with the heads at all the drive will spin down after a minute or two anyway, I guess because it's unable to locate track 0 on it's own.

Mystery
October 21st, 2013, 09:45 PM
The other spins up but the heads don't move at all. If you try to move them even just a wee bit the drive shuts down. And if you don't fool with the heads at all the drive will spin down after a minute or two anyway, I guess because it's unable to locate track 0 on it's own.
That's exactly the behavior I'm experiencing.
Plus I'm unable to locate the bumper that's supposed to be the cause of the problem. ;)

Edit:
I -might- be inching closer to a solution here.
I've finally been able to locate those sticky bumpers and oh my god are they ever sticky...it's more like a gooey mess in there. So far I've been able to get the heads to move out, but then nothing happens.
It seems I'm unable to get the piece of paper all the way in front of the bumper.

I'd love to remove that goo in there, but I have no earthly clue how to remove that without tearing apart the head assembly. I've read that some people were able to remove the bumper altogether, thanks to MikeS for the google tip, but I can't figure out how to do that.

Edit2 (don't want to spam):
I got it working again, at least temporarily to back up any data. There was a lot of that sticky stuff in there, and there still is, but after a while I got it working.

The bumper got so sticky and gooey, that the material was both on the frame and the moving part of the head assembly. I had to replace many paper strips, because they were covered in that material from both sides and got very sticky as well.

I'm not sure how long the disc will continue to work, especially after having it open for so long.

MikeS
October 22nd, 2013, 08:05 AM
...I'm not sure how long the disc will continue to work, especially after having it open for so long.It's definitely on borrowed time; just don't put any irreplaceable data on it and back up often ;-)

Glad you got your data off it in any case.