mathur@alberta.UUCP (Ambrish Mathur) (01/26/89)
I have recently been using the Zenith 286-LP AT-compatible with a 3.5" disk drive and MSDOS 3.3+. I can't seem to format a DS/DD 3.5" disk to 1.44MB even with the /t and /n parameters. On an IBM PS/2 this is possible (DOS 4.0). While the Zenith system supports 1.44MB for HD disks, it does not seem to allow this for the DS/DD disks although the manual vaguely hints this is possible. Is the check for HD disks a software feature? If it is I don't see why the 1.44MB formatting should be disallowed on the normal DS/DD disks since PS/2 's do allow it. Do any Zenith users know more about this? Any info on this problem/feature would be welcome. Please reply by e-mail. Thanks in advance. -- Ambrish Mathur mathur@alberta.uucp
mark@jhereg.Jhereg.MN.ORG (Mark H. Colburn) (01/26/89)
In article <2004@pembina.UUCP> mathur@alberta.UUCP (Ambrish Mathur) writes: >I have recently been using the Zenith 286-LP AT-compatible >with a 3.5" disk drive and MSDOS 3.3+. I can't seem to >format a DS/DD 3.5" disk to 1.44MB even with the /t and /n >parameters. On an IBM PS/2 this is possible (DOS 4.0). >While the Zenith system supports 1.44MB for HD disks, it does >not seem to allow this for the DS/DD disks although the >manual vaguely hints this is possible. I know that some versions of the Zenith 286 machines have a hardware check in them for high/low density disks. My Zenith 286 laptop has it. If you take a look at a HD disk, you will notice that it has an additional hole in it on the left hand side (looks kind of like another write protect hole, but without the slide...) My machine will check for the existance of that hole before writing HD disks. Yours may have the same "feature"... It has some advantages and some disadvantages, it just depends what you are doing and how you are doing it... -- Mark H. Colburn "They didn't understand a different kind of Minnetech Consulting, Inc. smack was needed, than the back of a hand, mark@jhereg.mn.org something else was always needed."
hundt@paul.rutgers.edu (Thomas M. Hundt) (01/28/89)
Bottom line: Certain drives (eg. my Teac) have a switch that detect the HD hole on HD media. PS/2s do *not* check. Thus, you can use any density media in any density on a PS/2, and everyone else may or may not have such luck. This has the unfortunate side-effect of making it possible for a PS/2 owner to write disks that his clone-owning friend can't read. I installed a front-panel toggle switch to disable the drive's sensor. Now I can save money and use 720k disks. :-) -Tom -- RRRRRR Thomas M. Hundt (aka hundt@occlusal.rutgers.edu) RR RR Gradual Student --- Electrical & Computer Engineering RR RR Rutgers University 201/932-5843(Lab) RRRRR 272 Hamilton St. #96 201/247-6723(H) RR RR New Brunswick, NJ 08901 RRR RRR Famous last words: "The virus ate it."
marc@dbase.UUCP (Marc Schifer) (02/03/89)
In article <2004@pembina.UUCP>, mathur@alberta.UUCP (Ambrish Mathur) writes: > with a 3.5" disk drive and MSDOS 3.3+. I can't seem to > format a DS/DD 3.5" disk to 1.44MB even with the /t and /n > parameters. On an IBM PS/2 this is possible (DOS 4.0). > While the Zenith system supports 1.44MB for HD disks, it does > not seem to allow this for the DS/DD disks although the > manual vaguely hints this is possible. Is the check for > HD disks a software feature? If it is I don't see why > the 1.44MB formatting should be disallowed on the normal > DS/DD disks since PS/2 's do allow it. The work around to the media sensor in most of the non PS/2 3.5 inch drives is to drill a hole (crude but effective if done carefully) in the other side of the disk, using another disk as a templet, to be shure you get the hole in the right sopt. The only problem with this is that the life expectancy of the DS/DD disk formated at double its capacity (1.44) is not very long. I used to use the 720k disks in a PS/2 Model 80 I had for a while and formated them at 1.44 (IBM dosn't check the media) but soon found that my disks were rapidly going bad, some to the extent of not being able to be refroamted. So I do not recomend this approach for saving money on disks unless you don't care about your data. Marc -------------- Standard Discaimer implied (i.e. TheseArntNoboddysOppoionsButMyOwnAndIamNotevenchureIWantthem) (i.e. Thesearntnobodysoppionsbutmyownandinnop
dts@cloud9.Stratus.COM (Daniel Senie) (02/05/89)
In article <2004@pembina.UUCP>, mathur@alberta.UUCP (Ambrish Mathur) writes: > I have recently been using the Zenith 286-LP AT-compatible > with a 3.5" disk drive and MSDOS 3.3+. I can't seem to > format a DS/DD 3.5" disk to 1.44MB even with the /t and /n > parameters. On an IBM PS/2 this is possible (DOS 4.0). IBM seems to be the only manufacturer allowing this. On the Toshiba 1.44MB drive I bought and installed today in my Z-386, there is a jumper to determine this behaviour. It seems that most people sense the extra hole in the diskette casing to determine high density. Note also that DSDD floppies formatted to 1.44MB in a PS/2 are likely to be unreadable in any other brand machine which has a 1.44MB drive... -- Daniel Senie UUCP: harvard!ulowell!cloud9!dts Stratus Computer, Inc. ARPA: anvil!cloud9!dts@harvard.harvard.edu 55 Fairbanks Blvd. CSRV: 74176,1347 Marlboro, MA 01752 TEL.: 508 - 460 - 2686