X400-Trace: US*UMASSMAIL*UMASS; arrival Tue,
            29 Dec 92 23:15:07 -0500 action Relayed
P1-Message-ID: US*UMASSMAIL*UMASS; 921229220823493-MTASATURN
UA-Content-ID: 921229220823493-
Newsgroups: comp.infosystems.gis
Date:         Tue, 29 Dec 1992 23:15:07 -0500
From:         Elias.T.Moning@EDUC.UMASS.EDU
Subject:      Reply to DOS operation and data format

>        Dear netter;
>
>        I have the following two questions not specifically related with
>        GIS.
>
>        (1) Disks formatted on different machines with different
>        DOS versions can not be used interchangeably. Does anybody know
>        why and the solution for the problem? According the MS-DOS 5
>        reference book, "to use a diskette with all versions of MS-DOS,
>        use /B and /1 switches which format the diskette for any MS-DOS
>        version and format only one side." I tried it, it does not work.
>        After I formatted a disk on an IBM ps/2 machine with DOS 4.00,
>        I tried to use it on a DEC 325c machine with DOS 5.00, I got the
>        following error message: "General failure reading drive a". Then
>        I was trying to reformt the disk on the DEC machine, the machine
>        does not allow me to do so, and keeps giving me the meaasage:
>        "Invalid media or Track 0 bad - disk unusable. Format
>        terminated." This may be a silly question, but I do need an answer.
>
>        (2) Can anybody recommand me some books regarding data formats,
>        particularly the ones we use frequently in GIS?
>
>        Thanks in anticipation.
>
>** END OF MESSAGE **

Regarding problem number 1,
in formating a diskette  you should be aware of it sizes, its capacity
and your floppy drives.  If you are formating a diskette, check first
what is its capacity: High Density (HD) or Double Density (DD);
and then check your floppy drive, if you have a newer computer the
chance is that your drives will read and write for both formats ie.
HD and DD.  Here the problem lies: These drives were set defaults on
HD no matter the drive size are (5 1/4 inches or 3 1/2), so if you try
to format a DD diskette in a HD floppy drive, there could be two thing
happened first, your DD diskette will be formated HD with the risk
that data saved in that diskette won't be readable by other computer
drives (I suspect that this might happen to you Shi), second, the
drive try to identify the existing format for the diskette and when
it found the formatting command and the diskette capacity does not
match it rejected it and give the bad media message.  Diskette
unformatable.

Solution:
if you have a DD 3 1/2 diskette to be formated in a HD 3 1/2 Floppy
make sure you have the following command at the DOS prompt:

C:\DOS >format a: (or b:) /n:9 /t:80

this will tell the computer to format your disk
at 80 track.  This the format fit for a 720 K 3 1/2 DD diskette.

if you are using MS-DOS 5.0 the command can be done as follows:

C:\DOS >format b: (or a:) /f:720

But if you are formatting a DD 5 1/4 diskette (360 K) the command
should be as follows:

C:\DOS >format a: (or b:) /4

or if you using MS-DOS 5.0  you can do the following:

C:\DOS >format a: (or b:) /f:360

the previous command will work in any DOS version.

So, please try and let me know if you still have the problem.

Regarding problem No. 2, I got solution to it, maybe someone
else can help you.


Regards,
Elias Moning.
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU