What about the IDE controller? Have you tried a different card?

Like, when I run Format C: /s, isn't it weird that command.com will get renamed to exactly CNMLAND.CNM..... on two different hard drives with different io boards and different cables? What's up with that?

dominusprog wrote on 2023-09-13, 19:15:

What about the IDE controller? Have you tried a different card?

I have two different controller boards that I can swap between, and neither of them seem to make a difference. Ditto with the slot I put them in.

Add these parameters for the hard disk.

1Heads: 56
2Cylinders: 262
3Sectors per cylinder: 32
4Sector size: 512

dominusprog wrote on 2023-09-13, 19:33:

Add these parameters for the hard disk. […]
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Add these parameters for the hard disk.

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1Heads: 56
2Cylinders: 262
3Sectors per cylinder: 32
4Sector size: 512

I should add these parameters regardless of the drive I'm using?

elsdrag00n wrote on 2023-09-13, 19:56:

dominusprog wrote on 2023-09-13, 19:33:

Add these parameters for the hard disk. […]
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Add these parameters for the hard disk.

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1Heads: 56
2Cylinders: 262
3Sectors per cylinder: 32
4Sector size: 512

I should add these parameters regardless of the drive I'm using?

Yes. The size will be set to around 230MiB.

The files getting renamed is suspiciously like memory errors.

Is the controller integrated? Does it do the same thing with a different drive?

Go into BIOS and turn off L2 Cache and try again. If that's not it, turn off L1.

If turning off L2 fixes it, you have a bad cache RAM chip. If turning off L1 fixes, you have a bad CPU.

I was able to have some success tonight with a 4th HDD that I found, though it's only 60mb. I'm not sure if it's confirmation that the other three drives I've tried are all bad, or if there's something else going on.

I'll try out the cache stuff and see if that helps with the other drives. I'd much rather have the 420mb one I recently picked up.

wierd_w wrote on 2023-09-14, 04:54:

The files getting renamed is suspiciously like memory errors.

Is the controller integrated? Does it do the same thing with a different drive?

It does do the same thing with other drives. Even seems to rename them files the same things. The controller is not integrated; I've been using the one that came with the machine, and when I started having trouble I picked up a second one that doesn't seem to make much difference.

I would start by cutting off the barrel battery and installing an external coin battery on jumper J2.
sometimes a weak battery can cause all kinds of havoc on the motherboard.

Either way that barrel battery needs to go before it begins to leak and destroys the traces on the motherboard.

I would also run a pass of MemTest86 on it overnight, to rule out bad RAM module

I would try using a smaller HDD. A lot of older BIOSes don't like drives larger then 528 MB. Others don't like going above 2 GB. Autodetect can go all kinds of wrong if you exceed that size. Some drives support a jumper setting to limit it's size to 2GB, sometimes that helps. Or you can manually reduce the number of cylinders reported by the drive (sometimes it is put on the label on top) to 1024 to prevent an overflow from happening in the BIOS code. But generally, using drives > 512 MB can cause trouble with those (older) 486 systems and was not period correct anyways.

That wouldnt explain the off by 1 errors in filenames and other wonk.

Issues with bios translation can be solved with either xtide bios on a nic, or with ezbios/disk manager ddo.

The off by 1 shit in filenames screams corruption in low dos memory.

See one other post online related to the COMMAND.COM renaming issue (in that case to CNMLAND.CNM) and that seems to have been caused by a 'faulty' IDE to CF adapter after using "format c: /s" - when the adapter was changed to a different one, the issue went away.

https://forums.overclockers.co.uk/threads/ide … blems.18829954/

digistorm wrote on 2023-09-14, 09:37:

I would try using a smaller HDD. A lot of older BIOSes don't like drives larger then 528 MB. Others don't like going above 2 GB. Autodetect can go all kinds of wrong if you exceed that size. Some drives support a jumper setting to limit it's size to 2GB, sometimes that helps. Or you can manually reduce the number of cylinders reported by the drive (sometimes it is put on the label on top) to 1024 to prevent an overflow from happening in the BIOS code. But generally, using drives > 512 MB can cause trouble with those (older) 486 systems and was not period correct anyways.

These limitations are indeed strange sometimes. I have been putting together late 486 system which is based on Zida 4DPS 2.11 with latest stable bios. I slapped a 1083MB HDD in it and BIOS detects drive parameters 100% correctly like the drive sticker says. Even better, everything works correctly. Except maximum space I have available is the famous 503MB, so I can't even make another partition. It feels almost like completely artificial limitation in BIOS.

CharlieFoxtrot wrote on 2023-09-14, 10:17:

digistorm wrote on 2023-09-14, 09:37:

I would try using a smaller HDD. A lot of older BIOSes don't like drives larger then 528 MB. Others don't like going above 2 GB. Autodetect can go all kinds of wrong if you exceed that size. Some drives support a jumper setting to limit it's size to 2GB, sometimes that helps. Or you can manually reduce the number of cylinders reported by the drive (sometimes it is put on the label on top) to 1024 to prevent an overflow from happening in the BIOS code. But generally, using drives > 512 MB can cause trouble with those (older) 486 systems and was not period correct anyways.

These limitations are indeed strange sometimes. I have been putting together late 486 system which is based on Zida 4DPS 2.11 with latest stable bios. I slapped a 1083MB HDD in it and BIOS detects drive parameters 100% correctly like the drive sticker says. Even better, everything works correctly. Except maximum space I have available is the famous 503MB, so I can't even make another partition. It feels almost like completely artificial limitation in BIOS.

It's from the CHS geometry schema--
https://en.wikipedia.org/wiki/Cylinder-head-sector

colluding with the INT13 CHS limits--
https://www.win.tue.nl/~aeb/linux/Large-Disk-4.html

this results in a maximum allowable geometry (for DOS), being (1024 cyls)(16 heads)(63 sectors per track)(512 bytes per sector) == 528482304 bytes.

This was addressed with improvements in the number of bits used by INT13, and later by ECHS, before finally being retired entirely for direct LBA.

This is where DDOs, (and better BIOSes) come into play.

A dynamic disk overlay is a small program that lives on the boot sector of the hard drive, rather than the boot sector for an OS. It loads BEFORE the OS, and take over the disk controller, loads a handler into RAM to handle software interrupt 13, then populates it with data it collects from interrogating the hard drive itself. To prevent itself being deleted/overwritten, it subtracts the first sector from the total sector count, and then lies afterward, presenting the **NEXT** logical sector as if it were the boot sector, so that disk utilities never touch its code.

There are 2 currently available from the days of Yore, that work with basically anything, and have been gifted to the masses for general non-commercial use. EZ-Drive and Ontrack Disk Manager.
https://www.philscomputerlab.com/western-digital.html

https://www.philscomputerlab.com/ontrack-disk-manager.html

Better BIOS is where XT-IDE comes into play. This is a small BIOS ROM routine that gets started by AT class computers before the OS loading routine starts. It can either be integrated onto an IDE controller, or be placed on a network card that has a socket for a PXE bios. (You place XT-IDE's bios there instead!) When the system tries to boot, this ROM routine executes, Takes over from the native BIOS's INT13 handler by altering the vector table, autodetects the connected drives, populates the INT13 variables, then passes on to OS load.

digistorm wrote on 2023-09-14, 09:37:

But generally, using drives > 512 MB can cause trouble with those (older) 486 systems and was not period correct anyways.

I put together systems and in late '94 or early '95 I purchased 1GB drives and put them in 486 systems. It was probably in '95 but it was before Win95, so we were using Win3.1. The BIOS on the boards simply had not caught up with support for these, but 1GB drives were certainly being used already and inexpensive. Early pentium systems likely had the issue too, I just don't remember them as well. We just used drive overlays and followed the instructions or you could purchase a board with ROM expansion and add it then as well. Sometimes you could get a BIOS update. I have a 486 system sitting right here that does not have large drive or LBA support and the manufacturer never provided an update to the BIOS dated mid-94. The OS could support large drives, so even if you didn't buy an add-in board for support, so a DDO was acceptable no-cost answer in those days. We didn't limit ourselves on what was cheaply available then.

elsdrag00n wrote on 2023-09-13, 18:57:

Hello everyone! I've been trying to build a 486 out of some parts that should work, but I've got this persistent problem with t […]
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Hello everyone! I've been trying to build a 486 out of some parts that should work, but I've got this persistent problem with the HDDs not holding formatting. It's reliably unreliable, and consistently inconsistent. A friend sent me here for help, since I'm at the end of my rope. I'll get right into the details:

Overview:
I purchased a used 486 dx 66 system from a pc recycler. Inside, it came complete except for the HDD. I've removed the Varta barrel and replaced with a coin cel, and to narrow things down in testing I've removed the sound card and a scsi card. This is the mainboard https://theretroweb.com/motherboards/s/mitac-trigon-ih4077c

Problem:
I can not for the life of me get a HDD to stick properly so that I can install programs. The BIOS does not correctly auto-detect the IDE settings of the drives I install; it also does not consistently get the same wrong answer when it tries. I can manually set them up, but then I generally get issues while using FDISK to set up the drive. If I can get past FDISK, Formatting is hit or miss. If I get past formatting, files tend to get corrupted. If I reset the PC, the entire thing usually gets set back to square 1.

If you leave the Virus Warning feature on in the BIOS, it will frequently trigger boot sector warnings while you use the PC.

Things I've tried:
I have two different IDE drives, two different I/O boards, and two different sets of ribbon cables to choose from. There are jumpers on the HDD drives and on one of the io boards. When the jumpers are set as they should be, none of it effects the issues I'm seeing, leading me to believe the problem lies elsewhere.

I'm unable to flash my BIOS as it's an EPROM. Regardless, I seem to have the latest version, though there's no way to know it's intact.

The machine runs perfectly fine off of the A drive. The HDD is the only area that seems to have issues.

Scandisk does not reveal bad sectors when I scan drives, but does complain about FAT.

When you do manage to get the HDD set up temporarily (manually enter IDE settings in bios, get lucky with FDISK, Format goes ok), files copied to the drive will get corrupted. The filenames themselves are scrambled, like COMMAND.COM will turn into CMNLOAD.CNM or something. It's not always exactly the same. Even the Volume name of the HDD will have it's letters scrambled slightly.

Only one time, I think when the BIOS seemed to actually guess the IDE parameters correctly, was I able to install and copy programs to the HDD and run them. Played some Prince of Persia. And then after a reset, it was all gone.

I feel like I'm taking crazy pills trying to get this thing to work. Does anyone have any suggestions? Thanks!

Basically, there are lists in the internet where you can find the right CHS setting for such old disks. Which ones do you have exactly?
If a disk is formatted and you do not know which CHS setting already is used, you may try to define the disk as type 1 and use a DOS boot disk with a diskeditor (like NU.EXE from Norton Utilities) to examine partition sector. Perhaps you can read the partition table to get at least number of heads and sectors.

If, perhaps your CMOS (BIOS) is losing contents and information about HDD too. Perhaps your coin cell does not work, or the Clear-CMOS jumper is set wrong.

You should disable Virus warning until you've setup all operating systems and boot managers.
However, I recommend to use "fdisk /mbr" on first disk, booting from a clean DOS disk. After that command, turn power off. Repeat it on second disk.

I have seen a disk of a mate that loses contents when it is transported.
I hope your disk is not that sensible too.