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First post, by adadak

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Hi, Folks
I installed a WD5000AAKB-00YSA0 hard drive. Now, I wonder how to manually set the CHS parameters given that the drive's label only specifies the LBA number. Please tell me how to get the CYLS/HEAD/PRECOMP/LANDZ/SECTOR table without it being specified on the label.

Reply 1 of 10, by dominusprog

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Try this

 Cylinder = LBA / (HPC * SPT)
Head = (LBA / SPT) % HPC
Sector = (LBA % SPT) + 1

LBA = logical block address
HPC = Heads Per Cylinder (reported by disk drive, typically 16 for 28-bit LBA)
SPT = Sectors Per Track (reported by disk drive, typically 63 for 28-bit LBA)

'%' is a modulus operation
'*' is a multiplication operation
'/' is a division operation

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Reply 2 of 10, by adadak

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dominusprog wrote on 2024-09-17, 12:05:
Try this […]
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Try this

 Cylinder = LBA / (HPC * SPT)
Head = (LBA / SPT) % HPC
Sector = (LBA % SPT) + 1

LBA = logical block address
HPC = Heads Per Cylinder (reported by disk drive, typically 16 for 28-bit LBA)
SPT = Sectors Per Track (reported by disk drive, typically 63 for 28-bit LBA)

'%' is a modulus operation
'*' is a multiplication operation
'/' is a division operation

The formula doesn't work in my case. If I assume the head number is 16 - the output CYLS exceeds the BIOS 6-digit limit, and if I assume it is 255, the BIOS calculates the disk size as 2521.

Reply 3 of 10, by jmarsh

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Just use the BIOS auto-detect feature?

Reply 4 of 10, by adadak

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jmarsh wrote on 2024-09-17, 13:53:

Just use the BIOS auto-detect feature?

Detects only 8.4 gigs at 16383/16/63 and that's what PartitionMagic also shows up

Reply 5 of 10, by jmarsh

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Then that's as big as it's going to get. Set it to LBA mode and enjoy.

Reply 6 of 10, by adadak

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I also tried 61273/255/63 configuration which should force the actual size but it ended up not booting at all with "primary master hard disk fail".

Reply 7 of 10, by Chkcpu

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Hi adadak,

When using a big 500GB drive with 48-bit LBA support from 2007 on a motherboard with a 2002 BIOS, there are some limitations to consider.

First, the latest P2B-DS BIOS is from 2002 and doesn’t know anything about LBA48, and is therefore limited to the LBA28 limit of 128GiB/137GB.
To break this 128GiB barrier, you need a BIOS with 48-bit LBA support but these came later in 2004, after the ATA-6 specification was published in 2003.

But your 2002 BIOS will allow drives up to 640GiB to be attached. But because this BIOS still uses 28-bit LBA, only the first 127.5 GiB of a larger drive can be seen.

But there is a workaround. When all code and data to boot the OS is placed in a partition below the 127.5GiB limit, the whole drive can be accessed by a 48-bit LBA capable OS after bootup!
So for this workaround, you have to use Win2000 with SP3 or higher, WinXP with SP1 or higher, Vista or later, or Linux with kernel 2.4.19 or later, as OS.

Now the issue with setting up the 500GB drive in the BIOS.
The BIOS HDD AUTO Detection should work fine here and setup the drive to the 128GiB limit in LBA mode. I’ve done this many times with the Pre 2004 Award BIOS and it works every time.
If you still need to use manual CHS parameters, enter 65535x64x63 in NORMAL mode and then select LBA mode which will translate the CHS to 16448x255x63 with a 135289MB size. Nicely within the 128GiB/137GB limit.

Cheers, Jan

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Reply 8 of 10, by adadak

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Chkcpu wrote on 2024-09-17, 17:47:
Hi adadak, […]
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Hi adadak,

When using a big 500GB drive with 48-bit LBA support from 2007 on a motherboard with a 2002 BIOS, there are some limitations to consider.

First, the latest P2B-DS BIOS is from 2002 and doesn’t know anything about LBA48, and is therefore limited to the LBA28 limit of 128GiB/137GB.
To break this 128GiB barrier, you need a BIOS with 48-bit LBA support but these came later in 2004, after the ATA-6 specification was published in 2003.

But your 2002 BIOS will allow drives up to 640GiB to be attached. But because this BIOS still uses 28-bit LBA, only the first 127.5 GiB of a larger drive can be seen.

But there is a workaround. When all code and data to boot the OS is placed in a partition below the 127.5GiB limit, the whole drive can be accessed by a 48-bit LBA capable OS after bootup!
So for this workaround, you have to use Win2000 with SP3 or higher, WinXP with SP1 or higher, Vista or later, or Linux with kernel 2.4.19 or later, as OS.

Now the issue with setting up the 500GB drive in the BIOS.
The BIOS HDD AUTO Detection should work fine here and setup the drive to the 128GiB limit in LBA mode. I’ve done this many times with the Pre 2004 Award BIOS and it works every time.
If you still need to use manual CHS parameters, enter 65535x64x63 in NORMAL mode and then select LBA mode which will translate the CHS to 16448x255x63 with a 135289MB size. Nicely within the 128GiB/137GB limit.

Cheers, Jan

I'm sceptical about the 127.5 limit. The thing is that after doing some math (CYLS = LBA / HEAD x SECTOR) I was able to set up properly a 320 GB CinemaStar under the same BIOS. And now with this 500 GB gentleman, I encounter a bootup failure (61273/255/63 at LBA)

Reply 9 of 10, by adadak

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UPDATE:
Everything has booted up just fine with the settings below:

Reply 10 of 10, by Chkcpu

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adadak wrote on 2024-09-17, 18:24:
Chkcpu wrote on 2024-09-17, 17:47:
Hi adadak, […]
Show full quote

Hi adadak,

When using a big 500GB drive with 48-bit LBA support from 2007 on a motherboard with a 2002 BIOS, there are some limitations to consider.

First, the latest P2B-DS BIOS is from 2002 and doesn’t know anything about LBA48, and is therefore limited to the LBA28 limit of 128GiB/137GB.
To break this 128GiB barrier, you need a BIOS with 48-bit LBA support but these came later in 2004, after the ATA-6 specification was published in 2003.

But your 2002 BIOS will allow drives up to 640GiB to be attached. But because this BIOS still uses 28-bit LBA, only the first 127.5 GiB of a larger drive can be seen.

But there is a workaround. When all code and data to boot the OS is placed in a partition below the 127.5GiB limit, the whole drive can be accessed by a 48-bit LBA capable OS after bootup!
So for this workaround, you have to use Win2000 with SP3 or higher, WinXP with SP1 or higher, Vista or later, or Linux with kernel 2.4.19 or later, as OS.

Now the issue with setting up the 500GB drive in the BIOS.
The BIOS HDD AUTO Detection should work fine here and setup the drive to the 128GiB limit in LBA mode. I’ve done this many times with the Pre 2004 Award BIOS and it works every time.
If you still need to use manual CHS parameters, enter 65535x64x63 in NORMAL mode and then select LBA mode which will translate the CHS to 16448x255x63 with a 135289MB size. Nicely within the 128GiB/137GB limit.

Cheers, Jan

I'm sceptical about the 127.5 limit. The thing is that after doing some math (CYLS = LBA / HEAD x SECTOR) I was able to set up properly a 320 GB CinemaStar under the same BIOS. And now with this 500 GB gentleman, I encounter a bootup failure (61273/255/63 at LBA)

Unless you are using a 2004 or later BIOS on your P2B-DS, that I’m not aware of, this 127.5GiB BIOS limit is very real.
To be able to set the full drive size manually in the BIOS Setup is no guarantee that this 500GB is actually supported. Filling the drive over the 127.5GiB limit will fail or simply corrupt the data on your drive.

In 2001/2002 nobody ever heard of a 500GB Harddisk. The biggest you could get was 120GB and was considered HUGE! 😉
Even when Windows XP was released in October 2001, it was limited to 128GiB. Only later with the released of Service Pack 1, 48-bit LBA support was added for support of larger drives.

The attachment Monitor_1_20240919-115557-335.png is no longer available

When you set the HARD DISK Type and MODE to Auto/AUTO for all 4 IDE channels like in the above picture, what do you get on the second BIOS summary screen for size on your 500GB drive? Should be close to 137GB. If so, this is a clear indication of the BIOS 127.5GiB/137GB limit.

The attachment Monitor_1_20240919-120553-284.png is no longer available

Jan

CPU Identification utility
The Unofficial K6-2+ / K6-III+ page