On Friday 08 February 2002 22:00, Matt Schalit wrote: > > ATA-Disk module (ADM) and it's write-protect features: > > > >Here is the 40pin 5V ADM schematic. This is using the LD017 > > > >controller. In the schematic R8 is used as an option for WP. > > I think this is the crux. It's being used. It's being > tied to ground by the presense of ground on IDE cable pin 30, > and the existence of a zero-ohm resistor, ie. a short to gnd.
a zero-ohm resistor is for circuit protection and yes pin 30 is ground on regular IDE as is pin 2. > Not a general feature if IDE I would agree. For a regular IDE drive, > disconnecting or strapping an IDE pin low or high, such as DIOW or > DIOR (23 or 25 I think) would interrupt the writing of command > signals to the drive's onboard controller. At least that's how I > understand it so far. Nope, pin 23 drops the acknowledgement of the drive itself out of the BIOS .... "no drive found to boot". I tried this a couple of days ago thinking the same thing. > > - If R8 is vacent, the device behaves normally (ie no > > write-protect) > > I see the exact opposite. It's gnd now according to the docs with R8 > present and it's write enabled. If you remove R8, then you are > trying to do the opposite, ie protect it. But is floating it > correct? If pin 30 is grounded (as normally done) and you add R8, R8 then grounds out pin 1 (reset) and _then_ the drive is write protected. <story> If you've now read this far, you get the cookie. Earlier today I hacked a jumper in an IDE cable between pin 1 (reset) and pin 2 (grnd) and started the P166. The BIOS acknowledged the flash drive (not a CF, but a regular IDE flash drive) and kept trying to reset the drive. It started to boot and failed. I thought, "well that sucks" and left it there. Just a couple of minutes ago, I was working by it and thought I might just boot it again, which I did, but this time it wasn't cycling the "reset" as it had before and booted. I logged in and tried to mount the drive ..... it gave me io errors and would not mount the drive. I rebooted 4 more times with the same exact results. I took the jumper out and booted again, I could mount and write to the drive. Apparently the BIOS updated itself after the first boot and decided to work for me. </story> In a nutshell, jumpering pins 1 & 2 on a regular IDE setup from around 1996 will write-protect a regular IDE drive. I will try this with a harddrive as soon as I get around to Syslinux'ing one. Can anyone else try and verify this for me ??? I won't guarentee anything at this point other than it worked for me on the only box I've tried it on. I apologize for being off-topic for using IDE instead of a ADM that I do not have. -- ~Lynn Avants aka Guitarlynn guitarlynn at users.sourceforge.net http://leaf.sourceforge.net If linux isn't the answer, you've probably got the wrong question! _______________________________________________ Leaf-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-devel
