se6@cs.vu.nl (Houweling E) (04/01/88)
DISK PROBLEM ============ Does anyone know if it is possible to diskcopy a 5.25 inch diskette onto a 3.5 inch floppy ? MS-DOS diskcopy won't do it, but in my opinion it should be possible to copy a disk to a HIGHER density diskette like this: >> READ sector #0, WRITE sector #0, READ sector #1, WRITE sector #1,...etc.. This should be possible on a machine which has both kinds of drives built-in, shouldn't it ? If this is NOT possible, why not ? If it IS possible, is there commercially available software which I could use ? +------------------------------------------+ | Rene' Baart | | School of Business Administration +-------------------+ | Free University of Amsterdam | EMAIL: | | Amsterdam, The Netherlands | bagron@cs.vu.nl | +------------------------------------| groedr@econ.vu.nl |--+ | Practical men, who believe +-------------------+ | | themselves to be quite exempt from any intellectual | | influences, are usually the slaves of some defunct | | economist. -- J.M. Keynes | +------------------------------------------------------+
rjchen@phoenix.Princeton.EDU (Raymond Juimong Chen) (04/02/88)
From article <976@tjalk.cs.vu.nl>, by se6@cs.vu.nl (Houweling E): > [suggests that there be a way to perform a DISKCOPY between different > media, at least from a lower density to a higher density.] I doubt that this is possible. Various information is kept in the boot record, like sector size, and possibly even cluster size, and the size of the FAT. This information varies depending on the density of the disk you are using. Thus, a sector-by-sector copy is [1] Impossible, since the sector sizes don't agree. [2] Possible but of dubious value, since the boot record no longer describes the medium. At best, you'll have a "good" disk with the desired information, but the "extra" storage capacity will be inaccessible. At worst, DOS will get confused and refuse to do anything useful with the disk. (For example, it'll expect to see the FAT starting at sector XX [since it thinks that it is a standard 3.5" disk] but the FAT is really stored at sector YY on 5.25" disks, so DOS is looking in the wrong place and goes out to lunch.) Disclaimer: This is not gospel; just an educated guess. -- Raymond Chen UUCP: ...allegra!princeton!{phoenix|pucc}!rjchen BITNET: rjchen@phoenix.UUCP, rjchen@pucc ARPA: rjchen@phoenix.PRINCETON.EDU "Say something, please! ('Yes' would be best.)" - The Doctor
dani@ritcsh.UUCP (Dani Kadoch) (04/08/88)
In article <976@tjalk.cs.vu.nl> se6@cs.vu.nl (Houweling E) writes: > Does anyone know if it is possible to diskcopy a 5.25 inch diskette > onto a 3.5 inch floppy ? MS-DOS diskcopy won't do it, but in my opinion > it should be possible to copy a disk to a HIGHER density diskette like this: > >> READ sector #0, WRITE sector #0, READ sector #1, WRITE sector #1,...etc.. > This should be possible on a machine which has both kinds of drives built-in, > shouldn't it ? If this is NOT possible, why not ? No, it is not possible for a program to copy disks in that way. The way DOS works is that for each different type of disk it accepts, it has a different scheme of writing to it. The size of the File Allocation Table (FAT) varies in different formats, for example. The FAT is simply a list of the clusters in use, and as you may realize, a 720K 3.5" disk has more clusters than a 360K 5.25" disk, hence a different size for the FAT. Another thing that changes size is the root directory, which simply keeps the names, location and other information about each file in \. Again, the larger the capacity of the disk, the bigger the root directory (generally.) If you want to copy between formats, the easiest way (in my opinon) is to use 'XCOPY A:\ B: /S' which will copy the root and all other directories from A: to B:. It will also automatically create all subdirectories needed in B:. However, this is not a completely infallible method, since hidden files and subdirectories will NOT be copied. I hope this helps, anyway. -- +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/+ > Dani Kadoch @ Computer Science House @ Rochester Institute of Technology < > UUCP: {allegra,seismo}!rochester!ritcv!ritcsh!dani BITNET: dnk8842@ritvax < +\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\+