🚀 go-pugleaf

>6500chng@ucsbuxa.ucsb.edu (B. N. Cheng) Writes:

>Recently, I bought a 3-M high density diskette and noticed that it
>was labelled 1.6 mb. Is it possible to format that many megs into the
>floppy using a standard AT 1.2 meg disk drive ?
>Perhaps there are programs or source codes that could do this.
>All my attempts have so far been unsuccessful.


1.6 Mbytes is the UNformatted capacity of the media.  It is possible to
gain additional formatted capacity by changing the disk format. For example:

80 Tracks X 2 sides X 15 sectors X 512 Bytes/sector = 1.288 Mbytes (less 
file system overhead: directory, fat ect.).

80 Tracks X 2 sides X 8 sectors X 1024 Bytes/sector = 1.311 Mbytes (less 
file system overhead: dir, fat ect.).

Bob Angelini

As a side note, there is a PD program called MAXI which will format 1.2
megabyte diskettes to 1.44 megs, and 1.44 meg diskettes to 1.6 megabytes.

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.

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

-Doug Pokorny
(drp@vpnet.chi.il.us)

+----------------------------------------------------------------------------+
|  Troubleshooting hint number one:                                          |
|                                                                            |
|    Symptom:  No power indicator, no screen display, no beep, no disk       |
|              activity.                                                     |
|    Solution: Make sure your computer is plugged in.                        |
|                                                                            |
|  "Just doing my part to help other computer users..."                      |
+-----------------+-----------+----------------------------------------------+
| Douglas Pokorny | drp@vpnet | "I've sold my OS/9 machine and gone 80386.." |
+-----------------+-----------+----------------------------------------------+

In article <26805b48-90.2comp.sys.ibm.pc.programmer-1@vpnet.chi.il.us> drp@vpnet.chi.il.us (Douglas Pokorny) writes:
> As a side note, there is a PD program called MAXI which will format 1.2
> megabyte diskettes to 1.44 megs, and 1.44 meg diskettes to 1.6 megabytes.
> 
> 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.
> 
> 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
> 
> -Doug Pokorny
> (drp@vpnet.chi.il.us)
> 

I currently use the MAXI program to allow me to put 420K onto 360K 
5 1/4 DSDD Disks.  At $0.21 a piece its a very cheap way to store information.
I believe MAXI will allow you to format 720K 3.5s to 800K or so.

On the 5.25s (and probably similar to the rest), the MAXI program formats
the disk at 10 sectors per track instead of 9, that gives you 400K for
space and then it also formats track 41 and 42 (40 & 41 for you binary thinkers)for another 20K.  

In using it the only thing I have found is, 1) almost every machine I've
tried (Clones, and orignals) require teh TSR program to operate correctly.
Without the TSR, you can read the directory but when you try and coyp 
files on tracks 41,42, you get seek errors.  2)  This is really only 
a useful program for archiving up data and storing away.  The method is
not reliable enough to be used constantly as a reqular disk with programs
and/or frequently modified data.  Usually the manufacturer only has
to insure that 360K will be available after a format and they don't 
guarantee or usually bother quality testing track 41,42.  You want to use
new, unused disks for the method.  I personally have about 600 5.25s       
formatted with MAXI and when I originally formatted them, about 25-30
disks failed to format without errors under MAXI.  So I suppose you could
say that about 5% of normal diskettes will fail.  

Oh, as to how it avoids modifying dos or a device driver, the TSR
program chains all of the BIOS and DOS disk write/read functions
and allows almost any program to run with maxi disks (Ive never found
one that doesn't)


Its a good program for archives like I said, but I wouldn't use it for
any constant use disk or any vital data.


Jeffrey P. Bakke     | Internet: bakke@plains.NoDak.edu | "Life... don't talk
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