r/DOS • u/Beef5nake • Jul 22 '26
Copying DOS Drive
I've been trying to create a copy of a bootable DOS drive onto a spare drive using 'format D: /s'.
However, when I try to boot the drive it isnt recognised? Is there something im missing?
I've made an image of the drive using hdd copy, but where the original drive is 80Gb and the target is 40Gb, I cant copy across.
Any advice would be appreciated!
This is MS-DOS 6.22
3
u/Scoth42 Jul 22 '26
Are you rearranging the cabling and/or master and slave config to make the drive that is D in that setup be first in line? Many older computers could only boot from the primary master, so if you're just rebooting after formatting it you won't see it boot any differently.
1
u/Beef5nake Jul 22 '26
Yes, im moving the drive to a seperate pc and setting the HDD jumper to master (only drive).
Ive tested the host drive in this PC and it boots fine.
2
u/Scoth42 Jul 22 '26
At the sizes you're running you could be running into max drive size issues. MS-DOS 6 itself only supports FAT16 which limits partitions to 2GB for a max of 8GB used. If it boots on the main PC then it sounds like it's at least set up okay.
The other potential issue is whether the other PC supports LBA or not. Many older (especially pre-486) computers only supported CHS addressing, a weird "LARGE" mode, or had other limitations on max drive size. Sometimes you'd be able to select the mode as part of IDE detection and sometimes not, depending on specifics. in any case you'll want to make sure both the working and non-working have the same drive parameters and mode in the BIOS, and even then that might be too big. 40GB would have been a ridiculously large drive for the DOS era
1
u/Beef5nake Jul 22 '26
So the working drive is 80Gb with a 2Gb partition for DOS, the rest is left blank.
Im essentially just trying to replicate this on the other PC, its exactly the same hardware and BIOS. The BIOS is also configured exactly the same.
2
u/Blah-Blah-Blah-2023 Jul 22 '26
What does it say when you attempt to boot? OS not found? Or something else? Is it even accessing the floppy?
1
u/Beef5nake Jul 22 '26
I think this may be where im going wrong. Off the top of my head it says 'no boot drive found'
Do i need a floppy with fdisk to make to partition active in a seperate PC?
2
u/Blah-Blah-Blah-2023 Jul 22 '26
Ah yes, other things ...
In FDISK, DOS will only boot for a PRIMARY partition.
I think you also need to set the 'Active' flag in FDISK.Also, FDISK D: /MBR will write a master boot record to your drive.
Could be one of those things.
1
u/Beef5nake Jul 23 '26
So i've been looking and i think what i need to do is create an fdisk floppy and boot from that and set the partition as active. I think this needs to be done with my original drive disconnected as only one can be active at a time.
As the the fdisk /mbr, I think i can run this from the floppy also, or within dos but i need to type 'fdisk /mbr 2'
Does this sound reasonable?
1
2
u/Feisty-Jeweler-3331 Jul 22 '26
40gb is too much for MS-DOS 6.22... it can only see 8gb
1
u/Beef5nake Jul 23 '26
Its running on an partition. I have an 80Gb (2Gb partition) that is working fine with 6.22?
1
u/Feisty-Jeweler-3331 Jul 23 '26
I suppose so but I'm unsure what are you trying to accomplish here.
1
u/Beef5nake Jul 23 '26
I have a DOS system that is fully working, it has specific software, drivers etc.
Im simply (clearly not that simple) trying to copy this drive (80GB) onto a spare drive (40GB) so that i can get a pc that is exactly the same hardware working.
The current 80GB drive works on both PCs. I just need to mirror thos drive (hopefully) to get the second one working.
If i can do it with just DOS, great. If not ill will look at other means, norton ghost etc.
Does this make sense?
1
u/Feisty-Jeweler-3331 Jul 23 '26
Is the second HDD getting recognized by the BIOS?
If that's the case, is it partitioned already? If not, you'll need to create a primary partition using fdisk, then do format /s to it...
After that it's just the matter of copying all directories and files to it.
You also might need to run fdisk /mbr on the target machine to make the new primary partition bootable there
1
u/Beef5nake Jul 23 '26
Yes, second HDD is recognised and is showing in the BIOS.
It has a primary partition on it using fdisk /s.
What i havnt done is the fdisk /mbr which i will try.
I beleive i also have to make the partition active outside by booting from an fdisk floppy as this cannot be done from within my workong dos system (without extra messkng around).
2
u/Blah-Blah-Blah-2023 Jul 22 '26
I think format /s put the system tracks on the disk but no COMMAND.COM, so you would need to add that. There is also the command "SYS D:", which (if I recall) does the whole job.
2
u/Beef5nake Jul 22 '26
I think it does copy the command com file. At least there was one there after the format /s.
Would you suggest doing a format d: followed by sys d: ?
2
u/Scoth42 Jul 22 '26
Format /s should handle everything in remotely recent versions of DOS. My recollection is ancient ones (like 2.x and below) used /s to set it up for booting but didn't copy files, but I could be misremembering.
In any case, format /s is equivalent to a regular format followed by a sys, so there's no harm in doing it
2
u/Beef5nake Jul 22 '26
Sorry, i should have mentioned the version. Its dos 6.22. Ive added this to the post
1
u/Der_Unbequeme Jul 23 '26 edited Jul 23 '26
MSDOS can only boot from the first drive (80h), the first primary activated partition
C:\> SYS D:
this will transfer the DOS System Files to drive D:
1
u/Beef5nake Jul 23 '26
So this would allow XCOPY to see the hidden system files and copy them accross.
On restart would these attributes be re-applied?
Would i still need to apply the mbr via fdisk?
Thanks for your response
1
u/Der_Unbequeme Jul 23 '26
first create a bootable floppy with FORMAT A: /S or SYS A:
copy FDISK.EXE and SYS.COM to floppy.
install new drive to the first primary connector.
boot from floppy and call FDISK /MBR & SYS C:
1
u/Beef5nake Jul 23 '26
Thankyou, i will give this a go.
1
u/Der_Unbequeme Jul 23 '26
Note !
MSDOS 6.22 can only access FAT formatted drives, max. 2048MB per logical drive.
1
u/Beef5nake Jul 23 '26
Sorry, so a format followed by the above command should make the drive bootable?
In a seperate PC
1
u/Der_Unbequeme Jul 23 '26
Format with switch "/s" will copy systemfiles to drive after formating
SYS A: will transfer systemfiles to selected and preformatted drive (A:)
7
u/smiffer67 Jul 22 '26
go to internet archive and get a copy of norton ghost v11 or below. best dos disk imaging there is.