OP wrote that

jude1977 wrote on 2026-07-15, 11:55:

I gave fdisk/mbr ago at the dos a pro t it gave me the usual options
Such as create a primary partition or a second partition
...

It shouldn't do that, it should do its job and exit.
So my next question would be with which versions of DOS version are we trying to /mbr, since it didn't exist until version 5 I believe.

I always use ontrack disk manager, from a bootdisk, to overcome bios limitations.
I use it to see the disk, format the disk in a way DOS will see it. and them overlay bios.

super easy, works always....

regular mecanical disks and CF-cards.

Hi all Ive taken a few photos of the way I try and create a partition through dos

These photos arnt in order as I had trouble putting them in order but all the photos
Are from when I tried to create a partition

There is a nondos partition that is 197mb in size. It is occupying the majority of the disk, according to fdisk.

There's a bit of 'unused space' before that partition begins. This is 'normal' practice for modern disk partitioning software that is GPT aware. (GPT partitioning is newer, and creates a larger structure than the MBR partitioning that DOS uses. One of the things present in GPT partition headers is a 'failsafe' or 'sacrificial' MBR structure at the start of the disk. It's there to protect the disk from old partitioning tools. Modern partitioning tools also 'align' disk structures at 1MB boundaries, instead of at sector boundaries like DOS does. Taken together, with this gap present at the start of the disk, this partition is 'probably ntfs', and was created by modern disk partitioning tools, like windows' diskpart / disk manager.)

You need to delete the nondos partition.

Once you do, you'll be able to create a 200mb partition.

We still dont know why DOS is reporting small chs style addressing-- is this dos 6.22, or something older?

For 2gb disk support with echs style addressing, you'll need at least dos 5?

Hi I’ve already tried to delete the non dos partition but it won’t let me delete it
It gives a message no partition to delete

I’m using dos 3.3 version

jude1977 wrote on Today, 10:19:

I’m using dos 3.3 version

I also find it odd that FDISK shows the non-DOS partition starting in the same place as the DOS one.

IIRC DOS 3 couldn't deal with drives >2G (who would ever have a drive THAT BIG! - 2G ought to be enough for anyone)

I'd suggest putting the drive into a "newer" MS system as a secondary (not-boot) drive, and see what that system shows for the drive partitions.

What I would try with the drive in the newer MS system would be to remove ALL partitions, then put the drive back in the EPSON and FDISK/MBR then create a partition, you may not be able to do "maximum size" (DOS 3.3 FDISK may not understand the drive well enough), you might have to pick a suitable partition size (say 20-500m)

Another thing you could try is to boot a later DOS and see if it understands the disk better, and if so you might be able to FDISK/MBR and create a suitably small FAT16 partition under that edition of DOS, before booting back to DOS 3.3 and using that partition instead of trying to create it.

And be aware, being of 286 era, the EPSON BIOS/HDcontroller may not be able to deal with a physically large drive at all - you may have to find a small drive!

Hi all I thought ide give a small hard drive a go I bought on eBay it’s a western 81 mb 70 cylinder 140
Heads wdc cc282m Ive connected it and it starts up fine but I thought ide try and partition it
But after I run fdisk it gives a message witch Ive shown in the photo Ive taken so you
All can see I thought I would have better luck using the hard drive but I’m still having trouble

jude1977 wrote on Today, 10:19:

I’m using dos 3.3 version

Dos 3.3 doesn't even have the /mbr parameter, I wrote earlier that this command shouldn't show the usual fdisk menu and there was a reason I asked this.

You need to boot from a disk with Dos version 5 or later, preferably 6.22. Do the fdisk /mbr and then launch fdisk and DELETE EVERYTHING, then create a new partition. Don't attempt anything unless you've completed these, it won't work.

^S0Kill can wipe everything from track 0 onwards, btw.

Looks like you have an SIIG EIDE controller.

I don't know why it's deciding that "system options" are not set after you changed the drive.

286s were "AT" era - hard drives were MFM with two "ribbon" cables (a wider one and a thinner one) from the (relatively dumb) hard drive controller to the actual drive.
IDE and "on board" conrollers didn't appear till later.

I don't know this controller - perhaps it stores it's own configuration information in some unused/hidden are of the root sector.
Do you have the setup disk it's requesting?

I hadn't even thought of this till now (It's been so long) - a 286 and IDE drives were not common and the whole "drive type" in BIOS wasn't a thing. It makes sense that it stores information about the drive geometry on the drive in a place where it doesn't need to know the geometry to access (like the 1st sector)

You are probably going to need the setup tool it's requesting.

This might also be why the other drive is "looking weird" - although if it weren't setup on this controller either, I would have expected to see the same "options not set" message with it as well (have you seen this message before?) - on the plus side, a 1995 IDE BIOS can probably deal with bigger drives.

PS: Don't trust the information it showed - I don't think it know the geometry of the drive - I highly doubt there are 70(140/2) platters in it!

konc wrote on Today, 12:16:

Dos 3.3 doesn't even have the /mbr parameter ..

Good point - all the more reason to use something later to set up the disk (You can get image for both 5 and 6.22 in DOSBOOT.ZIP on my site)

kinda funny: I've recently been playing around with booting old versions of DOS (from 0.9-1.0 to 6.22) including MS 3.3, IBM 3.3 but I've not actually installed any of these to a hard drive!

@DaveDDS

I posted a link to the manual for the card in question. It looks like it's really made for 386 systems. (As it mentions wanting to use multiword io modes, and ATA-2 style LBA access modes. Those dont need config information, as those are obtained with ATA-Identify) It does not disclose storing config data on connected drives.

It has optional (but turned off by default) ability to use ISA DMA during disk accesses. Based on OP's images, that functionality is turned off.

The manuals for the epson systems shows it was initially equipped with an MFM disk controller.

The system's motherboard has a Dallas RTC. This is the most likely source of the System Options Not Set error. CMOS checksum will be bad ater a hard poweroff, because the integrated battery has died.

Gsetup will smooth the wrinkle until the next poweroff, but a more permanent fix for the RTC is needed to stop having that error on start.

Setting a drive type in gsetup is probably to be discouraged.

RE: DOS versions

Dos 3.3 is not advisable. It has a maximum allowed partition size of 32mb!

I would recommend DOS5 as the oldest version.

(Dos 3 has support only for tiny partitions. Dos 4 was 'infamously bad' to the point everyone sane skipped it. Dos5 is thus the sanest choice if you want 'old dos')

Hi thanks for the info I decided to go back to using the sd ide adapter instead of the hard drive
Now the pc won’t even detect the sd ide adapter as it did before it gives a
Error message witch Ive taken a screenshot of and included in this message

Skip it with F1.

The dallas RTC is proably dead, and needs the delicate surgery. I dont recommend novices try the surgical correction. That's for greybeards.

The error is the system bios complaining the the cmos checksum is bad.

It will be bad after every poweroff, because the dallas RTC chip has a failed internal battery (and needs the surgery).

Full clarity:

Dallas semiconductor released a wildly popular 'fully integrated' realtime clock + battery package. The battery that provides power for the cmos memory is literally contained inside the RTC chip itself. While these did not leak, like many of the nicad barrel batteries that were alternatively used, when these batteries finally die, there isn't a good way to replace them. Even if the motherboard supplies an external battery header, the failed battery inside the RTC chip will short / ground it out, depleting the attached battery very very quickly.

There is 'a very delicate surgery' that can be performed, which very precisely cuts into the side of the dallas RTC package, and severs the power conductors leading to the internal battery. An external battery, like a CR2032 coincell holder, can be bodged onto the RTC package, and it will function correctly again afterward.

It very much requires very precise cutting. I'm a greybeard, and I would be uncomfortable doing it. I've seen people here successfully do it, all the same. It's a very advanced repair in my opinion.

However, your 286 will perniciously throw the system options not set error until this issue is resolved.

wierd_w wrote on Today, 13:40:

... The system's motherboard has a Dallas RTC. This is the most likely source of the System Options Not Set error. CMOS checksum will be bad ater a hard poweroff, because the integrated battery has died.

You *can* "fix" the Dallas RTC ... You have to "grind" off the top to replace the battery - I've done it a few times (mostly with Dallas NVRs - but fix should be the same)

... Dos 3.3 is not advisable. It has a maximum allowed partition size of 32mb! ... Dos5 is thus the sanest choice if you want 'old dos')

Agreed ... DOS5 is what I've settled on for my DOS systems. The only one I have still running 3 is a "Poqet" - DOS in ROM and CMOS RAM modules for drives (not big).

So does that mean that’s the reason the sd card is not showing up on the screen like it did
Before

It's the reason you see the 'system options not set, run SETUP from REFERENCE DISK, press F1 to continue' error.

Does this mean the computer is unusable now because of this or is it still usable
Can I still use the sd card adapter and sd card or are they unusable now as well