dos command

There's no DOS command for this... but you may download a file-splitter utility from www.download.com (or www.tucows.com) that will run from DOS and essientially do what you need.

i may be showing my age, but there is a DOS command for doing this, if you are running a full copy of DOS. In MS-DOS ver 6.x, there is a utility called MSBACKUP.EXE. It will do backups from a dos prompt to floppies. If you can find a copy of DOS, you could probaly pull it off the disk and use it.
Hope that helps.

There is a MSBACKUP command in older "full-blown" versions of dos (DOS 6.0 and higher)that I believe a previous poster has mentioned. It does have the ability for you to schedule backups and to only back up files that have changed since your last backup. It will span diskettes.

However you may also want to consider a slightly different solution: winzip. You can download a trial version from www.winzip.com. It allows you backup files and span diskettes if necessary. It also compresses your data (I do believe DOS backup does this as well, but not as efficiently). It has the advantage that it does not require the full version of dos to be used and therefore you could move files from one machine to another more easily. If you use MSBACKUP, you will only be able to restore the files to a machine that has a version of DOS installed that supports MSBACK, but winzip can be loaded on just about any machine (PC, anyway). Just a suggestion.

If above posts don't resolve sufficeintly ...

PKZIP 2.4g? or there abouts was DOS based and would let you span media (FD, Zip, etc.). Probably free ware by now, but not sure.

You should be able to find a copy with a net search.

Dos 4 and below had the commands BACKUP and RESTORE - fully command line

Dos 5 and up had msbackup had also a command line and menus you could use.

Problem with them is that you had to use the same dos command to restore the backup set.

www.pkware.com makers of pkzip and pkunzip have both a windows version and a dos command line version....

In pkzip you would issue the command that follows: pkzip -p -r -fv (drive letter and file name)

it's shareware and you can restore the data on any computer that can read zip files. Note Widnows 95 and 98 have in the Plus pack the explorer addin that allows you to add pkzipping to the right click of windows explorer.

Hope that helps.