10 Mar
2005
10 Mar
'05
7:30 a.m.
It would be nice to know for historical purposes
exactly which
vendors and when they started putting the firmware on the platter.
I don't think it goes quite that far, most drives only store the
geometry and block maps on tracks that are normally inaccessible to
the user. All the firmware is usually in the memory on the controller.
Seagate and Westarn Digital have had common electronics over different
capacities from about the 1GB drive size. On Seagates the mechanism
was interchangeable between ATA and SCSI controllers, something I used
to exploit to transfer large ammounts of data between my Amiga and PC.
I'll also add my guesses as to why swapping
platters is impossible.
When they build the drive, they clamp the platter on the hub, then
write it with servo information to let it find its tracks. Swapping
platters doesn't work because the two platters will never, ever sit
on the hub exactly the same way.
It doesn't matter, all that's needed is a LL format and all the data
tracks are re-written. Some manufacturers provide tools to do this as
just doing a format from the OS won't do a LL format.
The expensive places must have some way to pull a
platter with the
valuable info to be rescued, then re-align to find the true center,
then attempt to read the data.
No need, they use things like dynamic tracking, even on data only
platters, if needed but disassembling drives is always avoided if
possible.
Lee.
.
Send instant messages to your online friends http://uk.messenger.yahoo.com
10 Mar
10 Mar
9:28 a.m.
On Thu, 10 Mar 2005 15:30:59 +0000 (GMT), lee davison
<leeedavison at yahoo.co.uk> wrote:
The firmware-on-the-drive design is at least a Maxtor thing, not sure about
Western Digital, Seagate, or IBM , et al. Specifically, from what I've been
able to discover while researching my own dead drive is that it started with
Maxtor drives that were based on particular DSP chips... I'm guessing it
was a cost-savings measure to not have to put a large FLASH ROM on
the board, but to use the wads and wads of storage that could be accessible
It would be nice to know for historical purposes
exactly which
vendors and when they started putting the firmware on the platter.
I don't think it goes quite that far, most drives only store the
geometry and block maps on tracks that are normally inaccessible to
the user. All the firmware is usually in the memory on the controller. from a program on a smaller FLASH ROM or even a
masked-programmed ROM
(not positive about either one).
The loss of the ability of the DSP to read this area is the most common cause
of Maxtor drives coming up with 0/0/0 geometry (and is not what I was suggesting
was the cause of the initial poster's problem).
Seagate and Westarn Digital have had common
electronics over different
capacities from about the 1GB drive size. On Seagates the mechanism
was interchangeable between ATA and SCSI controllers, something I used
to exploit to transfer large ammounts of data between my Amiga and PC.
"Back in the day" of 1GB drives, which are nearly on topic by themselves, I
am pretty certain they were using more traditional techniques to design hard
drive boards. I'd have to say that these tricks will probably work through the
era of 6.3GB disks... I _think_ things started changing around the 10-20GB era.
I haven't personally had a board swap work since the days of the ST-251,
but I know it did work for a long time for IDE drives. I just wanted to point
out that in in some cases, it doesn't work the way one might expect anymore.
-ethan
6:50 p.m.
ZIP drives, and Compaq ATA drives will actually modify the data in some
sectors, there is indeed firmware control over the data written to disk.
Most often this is only for the boot block, but Compaq drives often have a
'fixed' partition with their diagnostics and remote admin crud.
These ATA drives are useless on other machines.
----- Original Message -----
From: "lee davison" <leeedavison at yahoo.co.uk>
To: <cctalk at classiccmp.org>
Sent: Thursday, March 10, 2005 10:30 AM
Subject: Troubleshooting ATA Drives..
It would be nice to know for historical purposes
exactly which
vendors and when they started putting the firmware on the platter.
I don't think it goes quite that far, most drives only store the
geometry and block maps on tracks that are normally inaccessible to
the user. All the firmware is usually in the memory on the controller.
Seagate and Westarn Digital have had common electronics over different
capacities from about the 1GB drive size. On Seagates the mechanism
was interchangeable between ATA and SCSI controllers, something I used
to exploit to transfer large ammounts of data between my Amiga and PC.
I'll also add my guesses as to why swapping
platters is impossible.
When they build the drive, they clamp the platter on the hub, then
write it with servo information to let it find its tracks. Swapping
platters doesn't work because the two platters will never, ever sit
on the hub exactly the same way.
It doesn't matter, all that's needed is a LL format and all the data
tracks are re-written. Some manufacturers provide tools to do this as
just doing a format from the OS won't do a LL format.
The expensive places must have some way to pull a
platter with the
valuable info to be rescued, then re-align to find the true center,
then attempt to read the data.
No need, they use things like dynamic tracking, even on data only
platters, if needed but disassembling drives is always avoided if
possible.
Lee.
.
Send instant messages to your online friends http://uk.messenger.yahoo.com
7 p.m.
Bob wrote:
ZIP drives, and Compaq ATA drives will actually modify
the data in some
sectors, there is indeed firmware control over the data written to disk.
I've used "IDE" (ATAPI) ZIP drives extensively on PDP-11 systems and on
PCs running Linux, and I've never encountered a case where the drive wrote
anything to disk other than exactly what it was told to write.
Possibly the Iomega Windows drivers might interfere, but I never use
those, since they won't run on either Linux or the PDP-11.
Eric
12 Mar
12 Mar
4:48 a.m.
I've used (or attempted to use) ATA ZIP 100 meg disks on my HP 1000
ATA disk controller (built on an 8052 platform).
ATA disks do indeed alter sector zero, in two different ways based on how
the 'Drive A:" jumper is set. You can find some references to this on the
web
in discussions of Linux drivers for these drives.
As for the Compaq drive, I have a Compaq 20 gig drive from a DeskPro
machine that has a partition that cannot be altered.
If I write over the first tens of sectors (writing all zeros) that drive's
firmware
will 'restore' the boot block and some number of later sectors.
When run on a conventional PC motherboard, its impossible to remove the
Compaq diagnostics partition. There is a huge amount of EPROM storage
built into this drive. Try as I might, I cannot make this drive act like a
normal
ATA drive.
I spent a lot of time trying to debug a perfectly working HP 1000 interface
when the real culprit was this drive. I installed a generic drive and all
the
problems vanished.
----- Original Message -----
From: "Eric Smith" <eric at brouhaha.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, March 10, 2005 10:00 PM
Subject: Re: Troubleshooting ATA Drives..
Bob wrote:
ZIP drives, and Compaq ATA drives will actually
modify the data in some
sectors, there is indeed firmware control over the data written to disk.
I've used "IDE" (ATAPI) ZIP drives extensively on PDP-11 systems and on
PCs running Linux, and I've never encountered a case where the drive wrote
anything to disk other than exactly what it was told to write.
Possibly the Iomega Windows drivers might interfere, but I never use
those, since they won't run on either Linux or the PDP-11.
Eric
10:53 a.m.
At 04:48 AM 3/12/2005, you wrote:
I've used (or attempted to use) ATA ZIP 100 meg
disks on my HP 1000
As for the Compaq drive, I have a Compaq 20 gig drive from a DeskPro
machine that has a partition that cannot be altered.
If I write over the first tens of sectors (writing all zeros) that drive's
firmware
will 'restore' the boot block and some number of later sectors.
do you mean 20 meg drive? the old deskpros with their 20 meg early IDE
drives were odd critters....
13 Mar
13 Mar
11:11 a.m.
Bob Shannon wrote:
I've used (or attempted to use) ATA ZIP 100 meg
disks on my HP 1000
ATA disk controller (built on an 8052 platform).
ATA ZIP drives are fairly rare; they only made them for about 18 months.
The vast majority of IDE ZIP drives are ATAPI instead. ATAPI is
essentially SCSI commands passed over an IDE transport; that's what
IDE CD-ROM, DVD-ROM, and writers, and tape drives use.
ATA disks do indeed alter sector zero, in two
different ways based on how
the 'Drive A:" jumper is set.
I haven't seen that behavior on the ATAPI ZIP drives. I did see it on
a few older ATA hard drives. I haven't seen it on recent ATA hard drives.
You can find some references to this on the web
in discussions of Linux drivers for these drives.
I must not be Googling the right keywords (e.g. linux ata driver write
sector 0), as I can't find anything.
By the way, when I wrote:
I've used "IDE" (ATAPI) ZIP drives
extensively on PDP-11 systems
that was an oversimplifiation. The ZIP drive on the real PDP-11 is
a SCSI ZIP, but there's an ATAPI ZIP in one of my Linux boxes running
a PDP-11 simulator. The simulator is used to run the same OS as the
real PDP-11, booted from the ZIP. I also 'dd' RT11 disk images to and
from the ATAPI ZIP. It has never corrupted the first
block.
Eric
7228
days inactive
7231
days old
6 comments
5 participants
participants (5)
-
bshannon＠tiac.net -
eric＠brouhaha.com -
ethan.dicks＠gmail.com -
geoffr＠zipcon.net -
leeedavison＠yahoo.co.uk