check the write protect slider on the sdcard? and you rebooted after writing the mbr?

I’m not sure whether the sd card has a wright protector slider I don’t think I saw one on it
I’ll have a look thoe no I didn’t reboot after writing the mbr the pc I’m using has got a
Dead bios battery does that make any difference if I reboot after writing mbr
Also I’m a bit confused what do you mean by writing mbr

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

... But when I tried to delete the partition it gave the same message as I wrote above ...

The last message I see you wrote above begins with "No space to create dos partition"

Is this correct, seems add to complain about no space to create when you are trying to delete...

I really haven't played with SDcards as drives (I have used CFcards as drives - they are much closed to IDE) so I really don't know why this would happen - I'm guessing some weird thing about how the card is formatted - does this happen with a different card?

Also, as @Picles suggested, make sure it's not write protected (I would hope for clear like "Write protect" error - but this is MS after all!)

SD cards write protect is a bit weird - a small tab that slides on the side, but it has no internal/electrical connection, it literally works by the writing device detecting the tab position - and some devices don't look at it at all (meaning the card can be written no matter where the tab is)

Always good to reboot after basic low-level system changes. There's no way to know what BIOS/DOS has cached which may not reflect the new state.

You should replace your CMOS battery - technically it shouldn't make a difference as long as you manually change all settings to where they should be ... but it's far to easy to forget one.
THis is especially true when trying to "figure things out" as you don't want subtle/norestored changes to be affecting your rest runs.

I just had a look at the actual sd card the switch is definitely in the unlocked position

Yes sorry for the confusion when I run fdisk in dos it shows there’s a non dos petition
On the card when I try to delete the petition it says can’t delete petition

jude1977 wrote on 2026-07-13, 14:09:

Thanks for all that information I hade a look for a prebuilt xtide card and they seem pretty hard
To find online as I can’t find any so I think I’d rather go for a hard drive

Texelec sells the Lo-tech XTIDE cards: https://texelec.com/product/isa-compactflash-adapter/

I've used these in a couple different Epson 286 builds along with CF-to-IDE adapters and appropriately sized CF cards. They work great as a CF solution for 286 systems.

Thanks for the message and link will check it out

It seems a waste to ditch a nice 16bit dual ide controller for an 8bit one, when all that's wrong here is which rom is in the socket. 🙁

Hi is there any advantage between a 16 bit and 8 bit ide controller
I don’t know much about them

I’d be happy to stick with your s if there’s a advantage

16bit controllers can send data much faster.
They also can use IRQs bigger than 7.

The ide specification was really made for 16bit controllers. 8bit ones like lotec cards, have to batch 8bit writes back to back to simulate 16bit io transfers, and other things.

Putting the AT flavor XTIde bios on the 16bit card is the best possible answer, but you dont have a blank 32k eeprom, nor a way to write it.

Suggesting you get the 8bit card is just a convenience catering to those facts.

Personally, i'd just burn and replace the rom on the 16bit card.

Alternatively, yank the rom out of the card's socket (so that NOTHING is at d800), use the cmos drive types, and use ezdrive.

In my experience a CF card with an 8-bit IDE interface doesn't matter that much on a 286 system. It still feels a lot faster than a traditional HDD, especially for HDD's of that era.

Maybe for a 386/486 the difference would be more noticeable.

Hi just a quick update on my problem Ive tried this time with my cf card in the
Adapter witch holds a cf card and tried again through dos to create a partition
And I have exactly the same issue and message come up as it did when
I tried with the sd card so using both cards gave the same issue and message as I wrote
A couple of posts ago so I’m beginning to think maybe it’s not the cards
I using that are the issue and maybe it’s something else causing the problem

id try a different ide cable

Just a quick update I tried a different cable as suggested it’s a older cable one that came
With my ide controller card that I got with it amazingly I can now create a partition
The only thing is I can’t seem to make the partition very large in space only 2 mb
I also tried copying dos to the ide sd card witch is showing up as partition c:
But it gives a message wrong dos version im not sure whether i used the
Write command as im not sure what it is i mean the command to copy
Files from floppy disk to sd card if any one could help me out I’d really appreciate it

Try to run the fdisk /mbr. Reboot again and check if the partition can be larger

Also, post pictures of the various fdisk screens when you are trying to create said partition.

Yes, try /MBR - always a good place to start when a drive seems "wonky".

With FDISK, can you see other partitions on the drive? if so, how big are they and how big is the drive? Is it possible you just don't have free space on the driver?

Indeed.. that's mainly what i'd like to see.

The "4) show partition information" screen, and the "1) create new DOS partition" screens.

To see if this is DOS trying to make a partition in the 1mb or so of leading disk space on MB-Aligned partitions modern OSes like to leave, or if this a translation related issue.