12 Mar
2005
12 Mar
'05
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