ray@micomvax.UUCP (Ray Dunn) (01/09/88)
The ONLY orientation of a hard disk that is normally not recommended, is
upside down, i.e. rotated through 180 degrees from its "normal" horizontal
orientation, or "bottom" of bearing up. Standing on either side, or on
its front or back is NORMALLY perfectly acceptable.
The restriction is only because of the platter bearing mechanism.
The likelyhood that the orientation will affect the head positioning is
EXTREMELY small (if it did, the disk under any orientation conditions would
be VERY unreliable - e..g. think of laptops etc).
There may be exceptions to this rule, however we have not come across any
in the PC environment.
The above is fact, the following is opinion.
On the subject of MSDos 3.3 and successors, without specific knowledge
currently of Microsoft's plans (and couldn't tell you if I had unless
it was "public" knowledge), but based on prior experience, I would think
it HIGHLY likely that a successor to 3.3 will appear.
I base this on several facts:
3.3 is not fully compatible with PCDos 3.3;
3.3 does not support 1.4Meg 3.5" floppies;
Dos on 'XT' type hardware (including PS/2 Model 30) does not support
multi-density disk drives (720K/1.4Meg 3.5", 360K/1.2Meg 5.25"), and although
the XT hardware/BIOS does not support the 'disk changed' hardware status that
makes the implementation easier, it IS still possible to handle this in no
worse a way (i.e. a kludge) than XT's and AT's currently handle the media check
function on 360K drives. This will probably be seen soon on non-vanilla
clones (i.e. those whose manufacturers support their own BIOS and Dos
releases) whether or not it is supported by MS;
DosManager is a likely candidate to be bundled with (into??) a future release
of Dos, one way or another.
One fact about 3.3 I have not seen mentioned in these postings: 3.3 is the
first version of MSDos which supports hard disk partitioning (i.e. vanilla
MSDos as supplied by MS).
This means that in many cases, manufacturers of PC's who implemented
partitioning themselves in Dos prior to 3.3, now have a compatibility problem
(it is unlikely that MS has chosen the same partitioning scheme).
To use Dos 3.3 on a disk partitioned using a pre 3.3 Dos, it is probable that
you will have to backup your entire disk, re-partition & format, then restore.
Ray Dunn. ..philabs!micomvax!ray
Disclaimer: The above opinions are my own, are not necessarily that of my
employer, a developer and manufacturer of XT and AT compatible
clones, and to the best of my knowledge, do not contain any
information proprietory to my employer nor any other organisation.hundt@anna.bellcore.com (Tom Hundt) (01/14/88)
ray@micomvax.UUCP (Ray Dunn) sez: |The ONLY orientation of a hard disk that is normally not recommended, is |upside down, i.e. rotated through 180 degrees from its "normal" horizontal |orientation, or "bottom" of bearing up. Standing on either side, or on |its front or back is NORMALLY perfectly acceptable. Now, what about hardcards? They stand the hard disk on its side, OK; but what if the whole PC is up on its side -- now the hardcard is either right-side-up or upside-down... perhaps the manufacturers should issue warnings, eg. "Warning: when installed do not stand the computer on its right side, only on its left". :-) And what about the poor guy who has TWO hardcards made by different manufacturers. He may not be allowed to stand his computer on *either* side :-) (But, he *is* allowed to turn it upside down.) Disklaimer: If it works for you, do it... Thomas M. Hundt / BELLCORE Morristown NJ / MRE 2L-350 x4955 ihnp4!bellcore!hundt hundt@bellcore.bellcore.com
Paul_L_Schauble@cup.portal.com (01/14/88)
Orientation of hard disks.... It is advised, though, to do the low level format in the orientation that the disk will be used in. Low level format is the one that writes sector marks on the disk. --Paul
leonard@bucket.UUCP (Leonard Erickson) (01/21/88)
In article <4810@bellcore.bellcore.com> hundt@bellcore.bellcore.com writes:
<ray@micomvax.UUCP (Ray Dunn) sez:
<
<|The ONLY orientation of a hard disk that is normally not recommended, is
<|upside down, i.e. rotated through 180 degrees from its "normal" horizontal
<|orientation, or "bottom" of bearing up. Standing on either side, or on
<|its front or back is NORMALLY perfectly acceptable.
<
<Now, what about hardcards? They stand the hard disk on its side, OK;
<but what if the whole PC is up on its side -- now the hardcard is either
<right-side-up or upside-down... perhaps the manufacturers should issue
<warnings, eg. "Warning: when installed do not stand the computer on
<its right side, only on its left". :-) And what about the poor guy
<who has TWO hardcards made by different manufacturers. He may not
<be allowed to stand his computer on *either* side :-) (But, he *is*
<allowed to turn it upside down.)
<
<
<Disklaimer: If it works for you, do it...
<
<Thomas M. Hundt / BELLCORE Morristown NJ / MRE 2L-350 x4955
<ihnp4!bellcore!hundt
<hundt@bellcore.bellcore.com
According to the paperwork from the manufacturers, for the several types of
drives we have at work, there are only *two* out of the possible six
orientations that are "forbidden".
They are mounting it with the "faceplate" either on top or on the bottom.
This makes sense as the head movement in such a position would be up and down!
(ie fighting gravity!)
--
Leonard Erickson ...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I used to be a hacker. Now I'm a 'microcomputer specialist'.
You know... I'd rather be a hacker."john@wa3wbu.UUCP (John Gayman) (01/23/88)
In article <710@bucket.UUCP>, leonard@bucket.UUCP (Leonard Erickson) writes: > According to the paperwork from the manufacturers, for the several types of > drives we have at work, there are only *two* out of the possible six > orientations that are "forbidden". > They are mounting it with the "faceplate" either on top or on the bottom. > This makes sense as the head movement in such a position would be up and down! > (ie fighting gravity!) That interesting. The AWS workstations manufactured by Convergent Technologies and sold by Unisys and NCR had a lectern which had a full-height 5 1/4 floppy and a choice of 5,10 or 15MB full-height hard disk *both* of which were mounted pointing UP. This is to say the front bezel points to the sky and the circuit card is facing towards the operator. Humm, I guess CT was never told they couldnt do that! :-) I beleive most of the disks were either Memorex or CMI. John -- John Gayman, WA3WBU | UUCP: uunet!wa3wbu!john 1869 Valley Rd. | ARPA: wa3wbu!john@uunet.UU.NET Marysville, PA 17053 | Packet: WA3WBU @ AK3P