In detail: 380XD Hard Drive Support (dual-boot)

[DeepestBlue]

Hello Forum,

New member here. I have a 380XD with a 40Gb HDD. I've been using Ontrack's Disk Manager Overlay so Windows 98SE can use the full size of the disk. Recently, I've replaced the hard drive with a 16Gb solid state drive, and wanted to set up a Windows 98SE / Windows 2000 dual boot. However, as I've discovered, just because Windows 2000 recognizes hard discs, doesn't mean it actually works, especially in a dual boot scenario. I decided to do some testing to find out what combinations of partition sizes work and do not work. Hopefully someone will find this information useful!

Methodology:
- Boot into Windows 2000 Pro setup from CD.
- Create first partition.
- Create second partition.
- Tell setup to install to the second partition.
- Allow setup to format the first partition FAT32 so it can install the bootloader.
- Setup then formats and installs to the second partition.
- On reboot, does Windows boot?

Code: Select all

Column One = Actual FIRST partition size created by setup
(Column Two) = FIRST partition size requested (a multiple of 1024)
Column Three = Actual SECOND partition size created by setup
(Column Four) = SECOND partition size requested (a multiple of 1024)
Column Five = Total partition sizes combined
Column Six = Did it boot?
Column Seven = Error message, if any

ONE  TWO      THREE FOUR  FIVE  SIX SEVEN
1026 (1024) / 2045 (2048) ##### YES -
2045 (2048) / 2045 (2048) ##### YES -
3071 (3072) / 2045 (2048) ##### YES -
4097 (4096) / 2045 (2048) ##### YES -
5124 (5120) / 2045 (2048)  7169 YES -
6144 (6142) / 2045 (2048)  8189 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1
7169 (7168) / 2045 (2048)  9214 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x3
8195 (8195) / 2045 (2048) 10240 NO  black screen

4097 (4096) / 3071 (3072)  7168 YES
5124 (5120) / 3071 (3072)  8195 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1
5124 (5120) / 3064 (3066)  8184 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1

2045 (2048) / 4097 (4096) ##### YES
4097 (4096) / 4097 (4096)  8194 YES
5124 (5120) / 4097 (4096)  9221 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1
6142 (6142) / 4097 (4096) 10239 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x3

1026 (1024) / 5124 (5120) ##### YES
2045 (2048) / 5124 (5120) ##### YES
3071 (3072) / 5124 (5120)  8195 YES
4097 (4096) / 5124 (5120)  9221 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1

1026 (1024) / 6143 (6142) ##### YES
2045 (2048) / 6143 (6142)  8188 YES
3071 (3072) / 6143 (6142)  9214 YES
4097 (4096) / 6143 (6142) 10240 NO  ntoskrnl.exe missing or corrupt, disk status 00000100 x1

MISC TESTS:

THREE PARTITIONS, WINDOWS 2000 PRO INSTALLED ON THIRD PARTITION

PART. ONE     PART. TWO    PART. THREE  TOTAL BOOTS?

4097 (4096) / 4097 (4096) / 4097 (4096) 12291 boot menu shows but goes to blank screen
2045 (2048) / 2045 (2048) / 4097 (2048)  8187 YES


LARGE PARTITIONS

None of these worked. All showed the error:

ntoskrnl.exe missing or corrupt, disk status 00000100 x3

Second partition sizes may look odd as I was using all remaining disc space rather than
a fixed partition size.

7169 (7168) /  8173
6144 (6142) /  9199
5124 (5120) / 10218
4097 (4096) / 11244
3071 (3072) / 12270
2048 (2045) / 13296
1026 (1024) / 14315

So what does this tell me? The total disk size is around 8Gb, regardless of partition layout. Mathematically, this would appear to be 8192Mb, although by the way Windows 2000 setup calculates it, it appears to be 8187Mb.

In theory, the partition layout should be irrelevant as long as the partition table does not address a partition that is beyond the BIOS's ability to address. So, what is the BIOS's limit? It's hard to say. Let's look at a couple of the test results that worked:

- Two 4Gb partitions [4097 (4096) / 4097 (4096)] worked. This is a total of 8194Mb, over the 8192Mb limit.
- One 3Gb and one 5Gb partition worked [3071 (3072) / 5124 (5120)]. This is a total of 8195Mb, again over the 8192Mb limit.

Both of these are a couple of Mb above the 8Gb limit.

However, consider this one:

- One 3Gb, one 6Gb partition. [3071 (3072) / 6143 (6142)]. Total 9214Mb. This worked.

But also consider this:

- One 5Gb, one 3Gb partition. [5124 (5120) / 3071 (3072)]. Total 8195Mb. This did NOT work, even through the reverse partition layout (3Gb first, then 5Gb) did work.


What can I conclude from this?

1) The BIOS has an 8Gb limit which can, under certain circumstances, be overcome to 9.2Gb
2) It would probably be "safe" to use a maximum total partition size of 8Gb (8192Mb), especially if the first partition is larger than the second.

I do appreciate that while I could probably use the OnTrack Disk Manager Overlay to set up two large partitions, I have found that drives set up in this way cannot be read natively on another Windows computer (for example, if the drive was removed and connected by USB to another computer). This can be problematic in certain circumstances.

I would welcome the forum's feedback and thoughts on this.