On Thu, 20 Oct 2005 15:09:43 +0200 (MEST), you wrote: Hi,
>as said, I updated my BIOS from "max 32 or 64 GB" (not sure which, >but crashed with bigger disks) to "max 128 GB". Then I plugged an >even bigger disk, and BIOS and FreeDOS were able to access the first >128 GB just fine, but FreeDOS hit the 128 GB barrier when trying to >enumerate all partitions and showed an error message (because it >cannot know that all partitions beyond the first 128 GB are Linux >ones which are uninteresting for DOS anyway ;-)). I would say that >this is pretty nice performance so far. Did you try this again on other motherboards? >Again, the problem is in BIOS. FreeDOS is able to use FAT32 (up to >2^28 clusters, recommended for max 128 GB but you can use bigger >drives if you want) and 32bit sector numbers (up to 2 TeraBytes). >It would be relatively easy to use 64bit partition positions to allow >"infinite" disk size with up to 2 TB per drive letter, but the normal >partitioning scheme itself is utterly unable to describe disks which >are bigger than 2 TB. Tom already suggested to support the successor >of partition tables: This will change the FAT32 behaviour. If the changes is downward compatible then everything works fine, but in the world of computing it's so hard to achieve. >That would support on-the-fly repartitioning (well, as pointed out >earlier, DOS reboots in seconds anyway, and some programs would get >confused by dynamic drive letter changes and it would take extra RAM) >and huge disks. But actually I have no idea why I would want my FreeDOS >to access more than the first 128 GB of my disk anyway ;-). The world is moving fast, I got someone hard disk with more than 120GB of digital camera's photos and DVD movies. >The BIOS limit to 128 GB (134 or so if you use "decimal GB") is >very common, and our UDMA2 driver has the ability to bypass it, >but as the kernel does not re-read partition tables after you >load UDMA2... Imagine the rest. A BIOS which sees 120 GB does >not necessarily see 160 GB. But a BIOS which sees 160 GB will, >unless it has a bug, see HUGE disks, up to at least 2 TB but, if >prepared for 64bit operating systems, even bigger than that. Except with a test on the latest PC, no one knows the theoretical's programming can work on physical drives or not. >Actually 32/64 bit operating systems do not care for BIOS disk >drivers at all anyway. Who knows ;-). Someone knows, just waiting for he/she to speak up. Rgds, Johnson. ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
