guitarlynn wrote: > > 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.
What does "circuit protection" mean? > > 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. I said the writing of *commands* not data. The lack of commands is what yields the lockup, from my understanding. I was not claming that write protect is possible by blocking DIOW or DIOR. Rather it's the exact opposite as you found. > > > - 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. The schematic show R8 exists. That's CS and my question at this point, "Does R8 exist on an LD017 controller?" > <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. Interesting. > Apparently the BIOS updated itself after the first boot and decided > to work for me. > </story> What BIOS are you referring to, and how does it update itself? > 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. I don't follow. Have you disconnect to wires to pins 1 and 2 on the drive, left them floating, and tied pins 1 and 2 of the cable side together? > Can anyone else try and verify this for me ??? I have a cable and an old IBM drive I can doink with. I'll let you know. > I won't guarentee anything at this point other than it worked for me > on the only box I've tried it on. Can I be a little lazy and ask you what the logic is that your trying to accomplish? What does grounding the reset line do? Regards, Matthew _______________________________________________ Leaf-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-devel
