martin@iris.ucdavis.edu (Bruce K. Martin Jr.) (10/21/87)
Can someone explaine why if a disk is formatted under MS-DOS 3.2, it
can be read under 3.2 or older, but if a disk is formatted, say under
3.0 or 2.x, it (sometimes) cannot be read under 3.2.
I suspect there is a bit set somewhere in the FAT, but don't know for sure.
It is one of those annoying things that is causing us headaches.
Is there anyway to get around it?
...bruce
Bruce K. Martin, UC. Davis, Div. of Computer Science
martin@iris.ucdavis.edu --or-- {ucbvax | lll-crg}!ucdavis!iris!martjujtr@wind.bellcore.com (tom reingold) (10/21/87)
In article <394@ucdavis.ucdavis.edu> martin@iris.ucdavis.edu (Bruce K. Martin Jr.) writes:
$
$ Can someone explaine why if a disk is formatted under MS-DOS 3.2, it
$ can be read under 3.2 or older, but if a disk is formatted, say under
$ 3.0 or 2.x, it (sometimes) cannot be read under 3.2.
This question was addressed and answered by PC Magazine when DOS
3.2 came out. When a disk is formatted, a signature is put in the
first few bytes of the first sector. It is a signature of the
company selling the DOS, i.e. IBM, Compaq, Zenith, etc. IBM's
version 3.2 refuses to read a disk if that disk's signature contains
a signature other than "IBM".
You can use debug to modify the signature on the disk. But the
easier way is to boot under a version preceding 3.2, copying the
files onto your hard disk, going back to 3.2 and reformatting the
disk and copying the files onto the disk again.
Yes, it's a real pain. Don't you love IBM?
I was using disks that were formatted with Zenith's DOS 3.1 and
the signature was "ZDS" (for Zenith Data Systems). I wonder if
all the other manufacturers use a three-character symbol. That
would make things easier.
Tom Reingold INTERNET: tr@bellcore.bellcore.com
Bell Communications Research UUCP: <backbone>!bellcore!tr
435 South St room 2L350 SOUNDNET: (201) 829-5119 [work]
Morristown, NJ 07960 (201) 287-2345 [home]wew@naucse.UUCP (Bill Wilson) (10/22/87)
In article <394@ucdavis.ucdavis.edu>, martin@iris.ucdavis.edu (Bruce K. Martin Jr.) writes: > > > Can someone explaine why if a disk is formatted under MS-DOS 3.2, it > can be read under 3.2 or older, but if a disk is formatted, say under > 3.0 or 2.x, it (sometimes) cannot be read under 3.2. > > I suspect there is a bit set somewhere in the FAT, but don't know for sure. > It is one of those annoying things that is causing us headaches. > Is there anyway to get around it? > You've got a problem. I am the PC technical coordinator for NAU and we have not experienced that problem at all. We even have a few people using DOS 1.x I would suspect the hardware before format differences. From DOS 2.0 DOS has been using a standard 9 sector per track format. ALL of the earlier formats are supported under this. I am surprised if you can get DOS 1.1 to support a DOS 2+ disk.
feg@clyde.UUCP (10/22/87)
In article <3180@bellcore.bellcore.com>, tr@wind.bellcore.com (tom reingold) writes: > In article <394@ucdavis.ucdavis.edu> martin@iris.ucdavis.edu (Bruce K. Martin Jr.) writes: > $ Can someone explaine why if a disk is formatted under MS-DOS 3.2, it > $ can be read under 3.2 or older, but if a disk is formatted, say under > $ 3.0 or 2.x, it (sometimes) cannot be read under 3.2. >.................. > > IBM's version 3.2 refuses to read a disk if that disk's signature contains > a signature other than "IBM". > > You can use debug to modify the signature on the disk. But the > easier way is to boot under a version preceding 3.2, copying the > files onto your hard disk, going back to 3.2 and reformatting the > disk and copying the files onto the disk again. If this is the easier way, I wonder what you would call difficult? But I must admit, I have trouble understanding what you are explaining here. Perhaps when you refer to "disk" you are not always talking about the same disk? If merely changing the name of the producer of the ms-dos is the object, look for this name from the 4th to the 10th byte from the beginning of the boot sector of any disk. Debug is the way to go. The name is not the only reason one system will refuse to read another system's disk. Some ms-dos have the boot record at a different address on the disk than others do, and certain programs, not finding the boot record will abort. The Leading Edge Model M ms-dos 2.11 and its twin the Sperry HT (ms-dos 2.11) have this problem. I don't know about any other Sperry HT ms-dos versions, but their ver 3.2 has corrected this situation and is now like the rest of the world. Forrest Gehrke
Les_B_Kooyman@cup.portal.com (10/24/87)
There is, if I recall correctly, a known bug with DOS 3.2 format. I know you can get an upgrade to 3.21 in the Microsoft case, simply by calling Microsoft and giving them your serial number. I did. I'm not sure about IBM.
ugfailau@sunybcs.uucp (Fai Lau) (10/25/87)
In article <1071@cup.portal.com> Les_B_Kooyman@cup.portal.com writes: >There is, if I recall correctly, a known bug with DOS 3.2 format. I know Which are you talking about? PC-Dos, or MS-Dos, or both? I have PC-Dos 3.20 and only notice problem in a 3270 work station in which the Format command insists that there is no room for the system when I execute Format /s. Even though I can always move the system manually using SYS. >you can get an upgrade to 3.21 in the Microsoft case, simply by calling >Microsoft and giving them your serial number. I did. I'm not sure about >IBM. If you're gonna upgrade your PC-Dos, might as well move up tp 3.30. Fai Lau SUNY at Buffalo (The Arctic Wonderland) UUCP: ..{mit-ems|watmath|rocksanne}!sunybcs!ugfailau BI: ugfailau@sunybcs