# How to (safely) clone MS-DOS and a working dos program?



## zachelaitus (Feb 5, 2017)

*I am a partner for a small business that uses three, 25-year-old 486 era PCs. We had a program designed for us by a start-up tech company in Okeechobee, Florida back in the 80's that we have used to account for daily files, act as a POS system, etc. Amazingly it has been exceptionally accurate and we have no plans to change. However, we have no more copies of this specific program. We have used the same HDD's for years now, and one has been on its last leg because you can hear the spindles grinding and slower respone. Unfortunately after a minor mishap of bumping the computer tower over from one of my employees (insert angry face and curse words) one of the HDD's bit the dust and now we are needing to clone one of the other computers.*

*I do not have any DOS cd's, nor am I able to use a USB, CD or floppy. Many of these old towers have lost the functionality of booting from floppy and none have USB. I am needing to find a program or figure out a way that I can safely plug a new HDD to one of the working 486's, clone every last bit of information, remove it, and be able to move it over to my new one.*

*I'm pretty familiar with PCs and the old bios mainframe and what not. Additionally, I was able to get a backup copy of the DOS program that we use and have it saved on a folder on my desktop. I of course attempted to merge the files saved on my desktop from the old one that died to the replacement one, however I get an error message so obviously it is not booting correctly.*

*Any help is greatly appreciated...*


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## TonyB25 (Jan 1, 1970)

Try VMware P2V.
http://www.vmware.com/products/converter.html


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## saikee (Jun 11, 2004)

You can clone any hdd (IDE, Sata, mSata, M2, ssd, 3.5", 2.5", USB flash, memory card...) with any Linux.

Linux has a command called dd that read a hard disk sector by sector and write the same on a target disk. Since the contents of any hdd is just 1 or 0 so the cloning is an exact mirror image of the original.

To do it just use any PC, Google it Distrowatch.

http://distrowatch.com/ is the centre web page of Linux and BSD systems which are all free. There is a top 100 list. Pick the top ones like Ubuntu and download its iso image. Burn the image into a CD or DVD. Such is a Live CD with a full blown operating system without being installed into a hard disk.

You then put the source disk, called inputfile or* if*, and the new target disk, call outputfile or *of* in a computer and boot up the Linux. Once booted up select a terminal and issue the following command to check which is the source and target by the sizes as Linux and Unix defines a disk as a device like /dev/sda and /dev/sdb etc.

*fdisk -l*

Assuming your source disk is device sda and the target is sdb one line of command

*date
dd if=/dev/sda of=/dev/sdb conv=noerror, sync
date*

and wait unit the output of the second *date* command gives you the output. dd does not report its progress so I add _*date*_ before it starts and when the output of the second _*date*_ is out it means dd has completed its task. For internal write at an old hardware say with usb3 connection the throughput is about 20MB/s. You can get about 60-100Mb/s if both disks are internally connected.  USB is a bottleneck and expect 5-10Mb/s speed with USB2.

The above is bomb proof as I have never had a failure, not even once. However if the hard disk is on its way out you will have bad sectors that cannot be read. The parameter * conv=noerror, sync* is to tell dd
to replace the bad sectors with zero and continue.

Linux and Unix have a rich utilities command set light years ahead of Dos/Windows and dd is a typical case of it. You can find an exhaustive example of its use in _http://www.linuxquestions.org/questions/linux-newbie-8/learn-the-dd-command-362506/ _

Also every hard disk manufacturer also provides a cloning software which may be used to achieve the same thing. There are other paid proprietary software too but I use dd because it the fastest and the simplest. I routinely upgrade the hard disk of the computer I purchase sometime immediately after I buy the machine because the largest hard disk is not always available with the latest models. The largest cloning I did is 8TB and it takes a day because at 100Mb/s a 8TB needs 8,000,000/100/3600=22.22 hours. dd is exceptionally reliable.

dd works with DOS because it clones only the binary pattern of the hard disk and has no interest in the filing systems and I can confirm having done this before.

Lastly I am curious if your Dos program able to run in the Command Prompt of other Windows. I expect it run in every version of Windows unless it is really really old.


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## kenbok51 (May 31, 2011)

If you originally loaded this program from floppy and are comfortable doing that again all you have to probably do is replace the floppy drive in the tower (I've seen them as low as $10). It's a cheap way to start but no quarantees. There are also legacy programs out there for floppy creation. I made a few Win95 and Win98se boot floppies a few years back with them. If you want I can look them up they would be on one of my older backup drives somewhere. I doubt you need floppy boot though for your problem.


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