Since MS-DOS supported four disk partitions per disk drive, the new FAT-12 file system worked up to 64-MB disks.
This change preserved the structure and size of the FAT-12 table, but allowed disk partitions of up to 16 MB. But an upgrade from 5.6 and probably 6.0 to 6.2 will continue to utilize DOS partition tables which have a limit of 2 TB.
Last edited by Platypus July 11th, 2004 at 05:42 AM. Microsoft solved the problem by allowing additional block sizes of 1 KB, 2 KB, and 4 KB. It looks like a clean install of 6.2 will allow you to use the entire disk no matter of size by using GUID partition tables. Is there any real value in using that large a drive in that system though? If I remember correctly, third party drivers were available from manufacturers to match specific hard drives and give 32bit disk access to larger partitions.
You will not be able to use 32bit disk access with a partition size above 512M using Windows own driver, so don't try to enable it if there is a partition larger than this. (A bug in MS-DOS means that it crashes if a drive has 256 heads, so its limit is a bit smaller than the BIOS limit but still almost 8GB. Similar to imdisk, you can set the size to KB, MB, or GB, by using K, M, or G after the number, respectively. When you set both to the same number, it sets a page file with a static size. The second is the maximum size for the page file. If it has no Autodetect capability, it probably can only see 512M, and you could try setting it up as 1024 Cyl 16 Head 63 Track. The CHS BIOS interfaces MS-DOS uses for disk access support drives up to just under 8 GiB, so this also about the limit for MS-DOS. The first 990M is the minimum size, or lower limit. It may refuse to boot (maybe hanging at drive ID), or may see the drive as 512M or a larger size, eg 2G depending on how advanced the BIOS is. Several things can happen if the BIOS cannot access so large a drive.
If the motherboard can successfully access all or part of the larger drive, you can create several partitions. Windows versions prior to Win95B do not use FAT32, so the maximum partition size is the FAT16 limit, which is 2GB with standard cluster size.