valley@gsbsun.uchicago.edu (Doug Dougherty) (05/04/91)
Upon what does it depend? The version of DOS? The kind of drive (LD or HD, 5.25" or 3.5") or what? I know you didnt used to be able to do this (Gosh, what grammar!), so that if, for example, you bought a box of preformatted disks, but needed them to be system disks, you had to reformat them all anyway. -- (Another fine mess brought to you by valley@gsbsun.uchicago.edu)
dj1l+@andrew.cmu.edu (Demian A. Johnston) (05/04/91)
When the first set of sectors on the disk are empty. The Bootstrap MSDOS.SYS (IBMDOS.COM) IO.SYS (IBMBIO.COM) need to be the first items on the disk. Demian J. =======> dj1l+@andrew.cmu.edu
JXS118@psuvm.psu.edu (Jeff Siegel) (05/04/91)
A (hopefully) complete answer on when you can sys a disk. For a disk to be bootable, the following conditions must be true: 1) The disk has a valid bootstrap sector. This is true of practically every disk formatted with the DOS FORMAT command. If you used some other formatting process, it may not be the case. 2) The first two directory entries on the disk are IBMBIO.COM and IBMDOS.COM, in that order. 3) The file IBMBIO.COM is the first file to occupy the data space. The clusters of the file must be in order and must be contiguous. 4) The file IBMDOS.COM is on the disk somewhere. Can be anywhere, and doesn't have to be contigiuous. Thus a disk is 'sys'able if the first two directory slots are empty and if there is room to put IBMBIO.COM down as the first file in the data space. However, I would bet the DOS sys command is stupid and therefore applies more restrictions than are actually necessary. Jeff
valley@gsbsun.uchicago.edu (Doug Dougherty) (05/04/91)
JXS118@psuvm.psu.edu (Jeff Siegel) writes: (Stuff deleted) >3) The file IBMBIO.COM is the first file to occupy the data space. The >clusters of the file must be in order and must be contiguous. >4) The file IBMDOS.COM is on the disk somewhere. Can be anywhere, and doesn't >have to be contigiuous. >Thus a disk is 'sys'able if the first two directory slots are empty and if >there is room to put IBMBIO.COM down as the first file in the data space. Well, that's a start, but it tells me things I already knew. The basic point is this: Early versions of DOS required that the slots (for the two system files) be allocated and reserved at format time. Hence, if a disk was formatted w/o /S, you couldn't SYS it. Period. You would have to reformat it with /S, in order to make it bootable. Somewhere along the way, this changed. Now, you can SYS a disk as long as it is empty. (Of course, I'm sure other restrictions apply, and your mileage may vary) -- (Another fine mess brought to you by valley@gsbsun.uchicago.edu)
amichiel@rodan.acs.syr.edu (Allen J Michielsen) (05/05/91)
In article <midway.uchicago.edu> valley@gsbsun.uchicago.edu (Doug Dougherty) >Upon what does it depend? The version of DOS? The kind of drive >(LD or HD, 5.25" or 3.5") or what? As several people have attempted to answer in different ways..... It depends on the major, minor, & vendor version of dos being used. Generically, early dos versions generally didn't work at all. Later version like 3.3 will generally work as long as no files reside in the 'reserved' locations. However, on a side note, both norton utilities and mace utilities, (and PC Tools 5.0 I think as well), ALL will make ANY disk bootable, just as long as enough disk space and directory/FAT space are available. I highly recommend owning one of these fine products. al -- Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University InterNet: amichiel@rodan.acs.syr.edu amichiel@sunrise.acs.syr.edu Bitnet: AMICHIEL@SUNRISE
mike@idca.tds.philips.nl (Mike Corrall) (05/06/91)
I always thought that one could write a system to a flexible disk *IF* no files had yet been written to that disk. The reason: the system files occupy the first two slots in the root directory. If these are not empty, the SYS command cannot work. -- ---------- Mike Corrall Voxnet: +31 55 43 2579 Faxnet: +31 55 43 2070 UUCP: ... !mcsun!philapd!mike Internet: mike@idca.tds.philips.nl [879.1.1.13] Papernet: PLG9i, Philips Information Systems, PO Box 245, NL-7300 AL Apeldoorn They said: Smile, things could get worse. So I smiled, and sure enough ...
IO92203@MAINE.BITNET (Scott Maxell) (05/07/91)
In article <1991May3.191723.24131@midway.uchicago.edu>, valley@gsbsun.uchicago.edu (Doug Dougherty) says: > >Upon what does it depend? The version of DOS? The kind of drive >(LD or HD, 5.25" or 3.5") or what? > >I know you didnt used to be able to do this (Gosh, what grammar!), >so that if, for example, you bought a box of preformatted disks, but >needed them to be system disks, you had to reformat them all anyway. >-- PC magazine has a utility - unfortunately can't remember the issue - called DISKPREP.COM that will make a disk sys-able. This can be done on any disk as long as there is enough space for the files on the disk. If there are no files on the disk, they can be SYSed anyway... //////////////////////////////////////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ +---------+ Scott Maxell -- Bitnet ->> IO92203 @ maine | | -- Internet ->> IO92203 @ maine.maine.edu | O | | | | "What I need is a computer that will do what I want it to +---------+ do, not what I tell it to do..."
alan@ukpoit.co.uk (Alan Barclay) (05/07/91)
In article <91123.230837JXS118@psuvm.psu.edu> JXS118@psuvm.psu.edu (Jeff Siegel) writes: > >2) The first two directory entries on the disk are IBMBIO.COM and IBMDOS.COM, >in that order. > >3) The file IBMBIO.COM is the first file to occupy the data space. The >clusters of the file must be in order and must be contiguous. > >4) The file IBMDOS.COM is on the disk somewhere. Can be anywhere, and doesn't >have to be contigiuous. > This only applies to PC-DOS, and a few versions of MS-DOS*, most MS-DOS use IO.SYS & MSDOS.SYS instead. *= NCR's version of MS-DOS for example. -- Alan Barclay iT | E-mail : alan@ukpoit.uucp Barker Lane | BANG-STYLE : .....!ukc!ukpoit!alan CHESTERFIELD S40 1DY | VOICE : +44 246 214241
cur022%cluster@ukc.ac.uk (Bob Eager) (05/08/91)
In article <Ec8V7vK00awO06V0ZW@andrew.cmu.edu>, dj1l+@andrew.cmu.edu (Demian A. Johnston) writes: > When the first set of sectors on the disk are empty. The Bootstrap > MSDOS.SYS (IBMDOS.COM) IO.SYS (IBMBIO.COM) need to be the first items > on the disk. Not quite right: a) The first two directory entries on the disk must be empty, so that the first entry can be made IO.SYS (or IBMBIO.COM in the case of IBM and a few other manufacturers) and the second entry can be MSDOS.SYS (or IBMDOS.COM). b) The MSDOS.SYS (IBMDOS.COM) file can go anywhere on the disk, and I don't believe it has to be contiguous except perhaps for very early versions. c) The first cluster of IO.SYS (IBMBIO.COM) has to be the first cluster in the file space (cluster 2). Prior to DOS 3.3, the whole file had to be contiguous; at DOS 3.3, the rest of the file is read in by the code in that first cluster. -------------------------+------------------------------------------------- Bob Eager | University of Kent at Canterbury | +44 227 764000 ext 7589 -------------------------+-------------------------------------------------