Path: utzoo!attcan!ncrcan!becker!hybrid!torsqnt!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!xrtll!silver
From: silver@xrtll.uucp (Hi Ho Silver)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: Re: 1.6 mb diskettes
Message-ID: <1990Jul1.160835.19622@xrtll.uucp>
Date: 1 Jul 90 16:08:35 GMT
Reply-To: silver@xrtll.UUCP (Hi Ho Silver)
Organization: Not around here, pal!
Lines: 51

$The program uses a "standard" dos format and does not require the user to
$load any sort of "driver" on 90% of IBM compatable hardware out there.
$The 10% of incompatable computers suposidly have "nonstandard bioses" and
$MAXI requires that you load a TSR called smax before it'll work.

   I've used two or three similar programs that all claim to not need a
driver on most machines.  I found it rather interesting that on all the
machines I've tested them on (including some genuine IBM hardware), they
have all refused to work without the driver loaded.  I haven't seen this
particular program, but I'd imagine it works similarly.

$Does anyone know how this program is able to:
$a) squeeze extra space out of any type of disk (i.e. 360k, 720k, 1.2m, 1.44m)
$b) do the above without modification to DOS or using a device driver

   Yup.  Standard diskettes use the following formats:

             360K     720K     1.2M     1.44M
# Tracks      40       80       80       80
# Sectors      9        9       15       18

   What these programs do is increase the number of tracks and/or sectors
on the diskette.  For example, to put 1.44M on a 1.2M diskette, you
simply increase the number of sectors per track to 18.

   The boot sector of any MS-DOS diskette includes such information as:
- the number of bytes per sector
- the number of sectors per cluster
- the number of sectors per track
- the total number of sectors in the volume

   By making appropriate changes to this information, you can tell DOS
how your diskette was formatted.

   One other note:  if you have double-density media (360K or 720K), it
is possible to format these as if they were high-density.  While you will
find a lot of sectors are reported as bad (particularly on the inner
tracks), this will usually provide a diskette with higher-than-normal
storage (typically it provides 800K on a 360K diskette).  But you can't
trust these diskettes; try it with some information you don't need and
you'll find an alarming number of errors.  While I would trust a diskette
formatted with a program like you mention above somewhat more than that,
I still wouldn't use it for any important information, nor would I use
it on more than one system (for reasons including the possibility of
needing a driver, and the minor differences between disk drives that mean
one may read it while another may not).  Just my opinion, though.
-- 
   /Nikebo \ Nikebo says "Nikebo knows how to post.  Just do it."\silver@xrtll/
  /---------\_____________________________________________________\----------/
 /yunexus!xrtll!silver (L, not 1)\ Hi Ho Silver \   just silver for short   /
/Silver:  Ever Searching for SNTF \  Life sucks. \  someone buy me a BEER! /