🚀 go-pugleaf

>>In article <682298720wnr@rosebery.demon.co.uk>,
>>Brian Sheehan <Brian@rosebery.demon.co.uk> wrote:
>>>I have a big 850mb enhanced IDE hard disk which I will have 
>>>to reformat to 500mb approx under dos (my motherboards too 
>>>old to support the full amount). This will leave me approx 
>>>300mb free which I understand can be used for a second 
>>>partition into which I can put an operating system like 
>>>OS/2. I dammed if I can understand how to do this?

Here is what I do, using the OS/2 FDISK to create these partitions:

 ----------------------------------------------------------------
| 1M   | Primary       |    |      | Boot manager                |
|------+---------------+----+------+-----------------------------|
| 69M  | Primary       | C: | FAT  | DOS/Win + swap              |
|------+---------------+----+------+-----------------------------|
| 255M | Logical drive | D: | FAT  | Programs + data             |
|------+---------------+----+------+-----------------------------|
| 127M | Logical drive | E: | FAT  | Programs + data             |
|------+---------------+----+------+-----------------------------|
| 50M  | Logical drive | F: | FAT  | OS/2                        |
|------+---------------+----+------+-----------------------------|
| 309M | Logical drive | G: | HPFS | OS/2 swap + programs + data |
 ----------------------------------------------------------------

Conner CFA850A
Cylinders: 1652
Heads: 16
Sectors / track: 63

 -----------------------------------------------------------------------------
|   |             |   Beginning   |     Ending    |  Start  |  # of   | # of  |
| P |  Type  Code |  Cyl Head Sec |  Cyl Head Sec |  Sector | Sectors |  Cyl  |
| - |  ----  ---- |  --- ---- --- |  --- ---- --- |  ------ | ------- | ----- |
|-----------------+---------------+---------------+---------+---------+-------|
| MBR/Part. Table |   0    0   1  |   0    0   63 |    0    |    63   |   0   |
|-----------------+---------------+---------------+---------+---------+-------|
| 1 | BootMg  10  |   0    1   1  |   2   15   63 |    63   |   2961  |   3   |
|---+-------------+---------------+---------------+---------+---------+-------|
| 2 | DOSbig   6  |   3    0   1  |  143  15   63 |   3024  |  142128 |  141  |
|---+-------------+---------------+---------------+---------+---------+-------|
| 3 | DOSext   5  |  144   0   1  | 1651  15   63 |  145152 | 1520064 |  1508 |
 ---+-------------+---------------+---------------+---------+---------+-------|
    | Ext. P. T.  |  144   0   1  |  144   0   63 |  145152 |    63   |   0   |
    | Logical D:  |  144   1   1  |  662  15   63 |  145215 |  523089 |  519  |
    | Ext. P. T.  |  663   0   1  |  663   0   63 |  668304 |    63   |   0   |
    | Logical E:  |  663   1   1  |  921  15   63 |  668367 |  261009 |  259  |
    | Ext. P. T.  |  922   0   1  |  922   0   63 |  929376 |    63   |   0   |
    | Logical F:  |  922   1   1  | 1023  15   63 |  929439 |  102753 |  102  |
    | - - - - - - + - - - - - - - + - - - - - - - + - - - - + - - - - + - - - |
    | Logical G:  | 1024   0   1  | 1651  15   63 | 1032192 |  633024 |  628  |
     -------------------------------------------------------------------------
Total:                                                        1665216    1652

Note that you have to tell the BIOS that you only have 1024 cylinders,
so that DOS doesn't see drive G: (but OS/2 will see it, of course).

Another note: if I had specified the OS/2 boot drive (F:) 51MB instead
of 50MB, it would not have been bootable, because it would have
crossed the 1024 cylinders boundary.  So, you basically have to do a
little calculation before you ask FDISK to create those partitions (in
MB, not in cylinders) so that the last cylinder of the last logical
drive DOS sees falls right at 1023.

Ken