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FDISK shows full drive size, FORMAT shows 4 gig.


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I've put a 40 gig drive into a circa 1998-1999 system with an Epox EP-BX3 motherboard, updated with the last BIOS release from 2000.

 

What's odd about this is that board never had a 4 gig hard drive size limit. It got updates to work with drives over 32 gig (and Y2K), then drives over 36 gig and finally up to 65 gig. http://www.motherboards.org/mobot/bios/Epox/EP-BX3/

 

I used FDISK from a 98SE boot disk to set up one primary partition and one extended partition with a logical drive, split 50/50. Not one issue with FDISK and the size of the drive.

 

FORMAT from the same boot disk only wants to format 4 gig. So I got Partition Logic's boot floppy and used it to make a primary active and formatted FAT32 LBA partition on the first 50% of the drive. (The drive in BIOS is set to LBA, the default that auto detection set.)

 

Then I copied the Win95 folder from an OSR2 CD to C: and during Setup scandisk says there's a FAT error and it must replace copy 1 with copy 2. Also, there's a huge "corrupt file", which I have it delete. Of course there's no "huge file" because all that is on it at that point is the Win95 folder and its contents. Cannot skip the "fixes" that are actually damaging the partition map, setup refuses to install to a drive with "errors".

 

Get done with Win95B setup and go to check the sice of C: and it is... FOUR GIGS. WTH?! Supposed to be around 15 gigs.

 

Are there replacements for format and scandisk that will see the true capacity of the partition like FDISK does? FDISK on the Win95B boot floppy also had no problems with the large drive. At least a replacement for scandisk I can put in the Win95 folder so it won't wreck itself while it's checking itself.

 

I do not want to have to resort to a drive overlay program as I'm planning on setting up a DOS 7.1 system on the other physical drive which is only 1.5 gig and I want to be able to access the 40 gig when booted to the small drive.

 

(Rapidly losing any sense of nostalgia I may have had for PC hardware of the late 20th century.)

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You said that you set the drive to LBA in the bios. According to this EP-BX3 manual: http://www.elhvb.com/mobokive/archive/Epox/manuals/bx300010.pdf

On page 4-25 it states that LBA mode works with drives up to 8.4 gb. It also gives an example of Large mode - which doesn't make sense - or I can't figure out how Large mode exceeds the size of LBA mode or what the upper end of Large mode is.

I recommend that you connect the drive to some other, more recent motherboard (made after 2002) with IDE controller and boot that board with a DOS floppy with win-98 DOS-7 fdisk and format (and chkdsk) and partition and format the drive on that board. Check the resulting partitions with chkdsk.

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I said I was using FAT32. Never mentioned FAT16 at all.

My bad, missed that part.

 

If it weren't Win95B as you said, could it have reformatted the partition at install time to FAT16? But that wouldn't yield a 4GB partition but a 2GB one.

 

I'd go with the Setup having pulled a strange/bad/old FAT copy that changed the partition size. Could've been the partitioning tool's fault. Try with another tool and/or on another system, as Nomen said.

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You said that you set the drive to LBA in the bios. According to this EP-BX3 manual: http://www.elhvb.com/mobokive/archive/Epox/manuals/bx300010.pdf

On page 4-25 it states that LBA mode works with drives up to 8.4 gb. It also gives an example of Large mode - which doesn't make sense - or I can't figure out how Large mode exceeds the size of LBA mode or what the upper end of Large mode is.

I recommend that you connect the drive to some other, more recent motherboard (made after 2002) with IDE controller and boot that board with a DOS floppy with win-98 DOS-7 fdisk and format (and chkdsk) and partition and format the drive on that board. Check the resulting partitions with chkdsk.

The "Large" mode is a very peculiar mode, very rarely used (or used only on very few hard disk models or in a very short period of time), in one of the (there were before and there have been after, lately the one with 4096 bytes sector and AF drives) disconnections :w00t::ph34r: between hardware manufacturers and Operating Systems changes, there were a few drives that had 16 heads (i.e. the same ones as the infamous 528 Mb limit):

http://www.pcguide.com/ref/hdd/bios/sizeMB504-c.html

but "went astray" (similar to LBA) with number of cylinders having more than 1024 of them.

The "large" translation consists in halving the cylinders and doubling the heads, hence a drive with 2048/16/63, 2048*16*63*512= 1,056,964,608 would become a 1024*32*63*512=1,056,964,608, BUT, it has happened that the issue may remain, i.e. there might be nonetheless a max total number of cylinders:

http://www.pcguide.com/ref/hdd/bios/sizeMB1970-c.html

http://www.pcguide.com/ref/hdd/bios/sizeGB304-c.html

http://www.pcguide.com/ref/hdd/bios/sizeGB305-c.html

What it seems (at least it seems reading between the lines of that motherboard manual) is that the LBA access they implemented is anyway a form of CHS :(, i.e. instead of doing what was normally done at the time, using an ebios translation because the OS could already use the extended int13h BIOS call, they left the "plain" int13h that has a limit in 1024 cylinders:

http://www.pcguide.com/ref/hdd/bios/sizeGB8-c.html

i..e. they made a "fake" LBA, as LBA in itself, by definition, has a limit in 232-1 sectors, i.e. the "current" known 2.2 Tb limit., it is possible that the system in question in reality is NOT affected by any of the above issues (otherwise SCANDISK would have thrown fits) but that - being an AWARD system, suffers from this (rare) one the date November 1998 cited in the manual seems like just right for this::

http://www.pcguide.com/ref/hdd/bios/sizeGB315-c.html

 

 

The 65,536 Cylinder (31.5 GiB / 33.8 GB) Barrier

This is a relatively new hard disk barrier that showed up in early 1999. It is yet another in a long series of limits caused by the inability of a BIOS version or type to handle a particular number of cylinders, much like several smaller barriers have been. It is often called the "32 GB size barrier", which is approximately correct anyway. :^)

In this particular case, some versions of Award BIOS cannot handle drives that have more than 65,535 cylinders. Since hard disk parameters usually use 16 heads and 63 sectors, this works out to a capacity of about 33.8 GB or 31.5 GiB before trouble occurs. As of about June 1999, this problem had been corrected, so it is most likely to show up on systems purchased before that month.

I must say that I find this to be a rather strange hard disk barrier, because hard disks above about 8 GB in size no longer really use discrete geometry for access; they are instead addressed using LBA and a flat sector number from 0 to one less than the number of sectors on the drive. This 65,536 cylinder problem must be a remnant of some older code, or something related to compatibility with older hard drives. Regardless of its origin, many system owners will have to deal with it.

 

And -strangely enough - it could even make some sense if we are/were to listen to MS when they declared that Windows 95 would not be suitable for disks larger than 32 Gb:

http://www.pcguide.com/ref/hdd/bios/sizeGB30-c.html

https://web.archive.org/web/20000609233118/http://support.microsoft.com/support/kb/articles/Q246/8/18.ASP

In a nutshell, if you have a disk larger than 32 Gb use NT 4.00 or Windows 98 as Windows 95 might have issues.

https://web.archive.org/web/20000611135126/http://support.microsoft.com/support/kb/articles/Q243/4/50.ASP

 

@bizzybody

Get RPM (Ranish Partition Manager) and check how the disk is seen by it (both in LBA and Large mode) under the actual OS you will be using.

Let's see if we can understand if the issue is connected to BIOS, to the Windows 95 or from a combination of the two (I am assuming that you already tested the actual hard disk with it's manufacturer utility and that it passed the tests).

 

It is likely that you will need to either use a frankenOS (mix of 95 and 98) or exclude an area of the hard disk if you use Windows 95. :unsure:

 

jaclaz

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Unfortunately Wim's BIOS doesn't list Epox EP-BX3's among the patched BIOS versions they offer. :( But you could at least try to place a request in the forum, maybe someone could take a look at it and get it fixed... if the gurus are still around and the issue is in the BIOS.

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And -strangely enough - it could even make some sense if we are/were to listen to MS when they declared that Windows 95 would not be suitable for disks larger than 32 Gb:

http://www.pcguide.com/ref/hdd/bios/sizeGB30-c.html

https://web.archive.org/web/20000609233118/http://support.microsoft.com/support/kb/articles/Q246/8/18.ASP

In a nutshell, if you have a disk larger than 32 Gb use NT 4.00 or Windows 98 as Windows 95 might have issues.

https://web.archive.org/web/20000611135126/http://support.microsoft.com/support/kb/articles/Q243/4/50.ASP

What?!? :o  jaclaz falling for Microsoft FUD??  :whistle:  Maybe you should see a doctor... are you feeling OK? :lol:

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My intention is to split the disk 50/50 into a primary partition and an extended partition with a logical drive, so Win95B shouldn't have an issue with too large of a partition.

 

From the info posted on this thread and the change notes on the various BIOS releases, it looks like Epox had several issues with this board and hard drives. I've posted at Wim's and another BIOS site. If someone could do a 128 gig patch and do it up properly so there's no odd glitches, then it might work.

 

I'm going to hook the drive up to a Win7 box and see what AOMEI can do with it. If I can adjust the partitions with that while leaving the current Win95B install intact, it hopefully will work - as long as scandisk is not allowed to "fix" it.

 

I want to see if I can run the DOS software for my proLIGHT PLM2000 CNC milling machine in Win95, should have little or no interference with the RS232 port. It will *almost* work in XP. Can get it to communicate with the mill but XP keeps butting in and cutting off communication through the com port.

Edited by bizzybody
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The board documentation describes the LBA Mode as a BIOS mediated translation from CHS to LBA.

There is no mention of Interrupt 13 Extensions for full LBA use.

Since you used FDISK in percentage mode, it probably created two 4GB Partitions.

A DDO is mandatory for proper operation of a larger drive with this BIOS.

I have a number of DDOs suitable for this purpose.

Windows 95 is NOT limited to 32GB. I am running it with 2TiB with my Hard Disk Patch. Otherwise it is limited to 137GB.

Edited by rloew
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I entered the number of cylinders to make the primary partition 50% of the size, didn't enter 50%. Then I let FDISK make the extended partition use the full remaining capacity.

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Cylinders, clusters, whichever the number was in FDISK, I divided it by 2 and entered that for the primary partition. It's only been 10~15 years since I've setup a PC with 95. :P

 

I have Win95B seeing the full size of the partitions, after using other utilities on it with the drive connected to a PC running Windows 7. I was able to leave the fresh 95B install on it.

 

I am not going to run 95's scandisk on the drive, since that was seeing "errors" and damaging the format while "fixing" them. Don't want to try another clean install if scandisk is just going to break it again.

 

Hopefully someone will decide to mod the BIOS and fix whatever is wonky with it. First time I've ever seen a case like this where FDISK would partition the drive but FORMAT would not format the full size fdisk created. (Semi-fondly recalls the days of using DEBUG to access MFM controller BIOS low level formatting and using EDLIN and COPY to write autoexec.bat and config.sys files... on my very first hard drive of a massive five megabytes.)

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Maybe you should try filling up the extended partition with dummy files to check if the BIOS won't wrap around the 8.4GB limit, destroying the Windows files and anything at the beginning of the drive CHS-wise. To avoid reinstalls you may create partition/drive image(s) beforehand, easily restorable.

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What?!? :o  jaclaz falling for Microsoft FUD??  :whistle:  Maybe you should see a doctor... are you feeling OK? :lol:

 

Not really, (in the sense that I feel  OK :yes: and I have never trusted MS documentation :no: ) I was hinting that maybe - at the time - the good AWARD guys fell for it and that the queer 65536 cylinders limit was *somehow* connected with this failed perception, and that IF someone actually believes :w00t:  to what Microsoft said, they did say that Windows 95 would NOT be suitable for larger than 32 Gb disks.

 

jaclaz

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