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linuxlove
August 26th, 2013, 12:03 PM
Today I bought a Zenith SlimSport 286 laptop. It seems to work; I can hear the floppy drive and hard drive spin up and whir like normal but someone set a boot password where it won't boot from anything. It will dump me into a memory monitor if I hit ESC, maybe I could use that to clear the password? Or will leaving the CMOS battery out clear it?

SpidersWeb
August 26th, 2013, 01:17 PM
Usually removing the CMOS battery clears that kind of thing. I'd leave it out for a while.
But first try:
"Zenith"
or
"3098z"

linuxlove
August 26th, 2013, 06:07 PM
Neither of those passwords worked. I guess I'll leave the thing unplugged all night and see if that fixes anything. I did read the manual and it did say that most of the configuration data (including the password) was stored in some form of non-volatile storage though...

Stone
August 26th, 2013, 06:12 PM
Did you try booting from a floppy?

SpidersWeb
August 26th, 2013, 06:21 PM
Neither of those passwords worked. I guess I'll leave the thing unplugged all night and see if that fixes anything. I did read the manual and it did say that most of the configuration data (including the password) was stored in some form of non-volatile storage though...

I think you'll need to disconnect the internal CMOS battery for a while, until that non-volatile storage becomes volatile.

Stone - yeah I wondered if it'd be a software solution on the HDD, but this model did have a password feature that's as he describes, thing is basically unusable until it's cleared. Not sure how it does it or where it's stored (my guess was CMOS). Might be interesting to see if the problem disappears if the HDD is removed though.

Edit: I did dig up this piece of text, in a thread regarding an NEC ProSpeed 286 (it's not an answer, just thought it might be helpful to keep in mind):


The Zenith laptops have simular features. The internal chip is an E^2
PROM and will not forget no matter how long you disconnect the power.
The only fix is to open it up and on powerup short out the serial output
line so that the output is 000000. This will then let you clear the
password but only on the first try. Of course I don't remember the chip
and if asked I don't remember anything.

and this in reference to a Zenith SlimSport 286 (translated by google):


Yes, but nothing. However, there are managed in a different way. I found the chip
the cmos, I downloaded the datasheet and I made a bridge on his leg
reset. Now is no password and I can access the bios, but you are presented
other problems, such as: Drive not read in reference to the hard-disk. I ask
other advice. Thanks!

(I'm bored, so have been searching google groups)

linuxlove
August 26th, 2013, 07:04 PM
Pulled the hard drive, no change.

The thing asks for a password no matter what you try to boot into - hard drive, floppy disk or even system setup. It will drop me into the Monitor though; couldn't I theoretically bypass the password screen and go straight to Setup? It would help if I knew where to JMP though.

Also, this thing is loaded with cheap metal screws that strip out if your screwdriver is just the tiniest bit out of spec. >_>

SpidersWeb
August 26th, 2013, 07:21 PM
I'd say so, if the monitor lets you execute code via a jump. I'm not familiar with the monitor tool.
I have one of these in parts (its dead), so I might have a poke around when I get home, could potentially read the EPROM contents.

I didn't have problems opening mine, but I have a lot of screwdrivers.

linuxlove
August 26th, 2013, 07:45 PM
I think I can do that, the monitor lets me add data to the registers and then execute it. Gonna be fun trying to directly manipulate the registers... I dunno, I think the execute command lets me execute a program in ROM if I specify the address:


G: Execute (Go) G [=<addr>][,<breakpoint>]...

SpidersWeb
August 26th, 2013, 09:07 PM
What happens if you type "setup" on the monitor? Does it ask for the password again?

And by the looks the CMOS battery is easy to get too (if you wanted to try it): http://www.nightfallcrew.com/gallery/zenith-slimsport-286-iwl-286-2/IMG_4297.jpg
I wish all my machines had a nice little compartment like that.

Chuck(G)
August 26th, 2013, 09:14 PM
Given the age of the thing, I'd suspect a small 8-pin EEPROM/NVRAM; perhaps something by Xicor, if memory serves. These things were also used for some ISA PnP settings storage, NIC settings, etc. There's even one on some Intel Aboveboard 286 memory cards.

SpidersWeb
August 26th, 2013, 11:13 PM
I'm not sure who makes it, but there is an EEPROM (separate to the 1mbit EPROM), which keeps it's settings without power.
Part is located next to the FDD connector, marked '10GB', component is 93C46-037 - which seems to be a 256kbit CMOS Serial EEPROM.
Assuming what I read was true, you'd need to short out pins 4 and 5 (Data Out and Ground) during power up. That sounds rather nasty, maybe someone else has a better idea.

Now I've pulled mine out, I should clean it and try again. It's battery leaked before I got it but there is not trace damage. (remove yours if it doesn't work, because it's nasty).

Chuck(G)
August 26th, 2013, 11:32 PM
1Kbit, not 256Kbit. Pull the chip and short 4 and 5, which will cause the chip to appear as if it it's returning 000000....

SpidersWeb
August 27th, 2013, 12:52 AM
1Kbit, not 256Kbit. Pull the chip and short 4 and 5, which will cause the chip to appear as if it it's returning 000000....

You'd probably want to short it without pulling it (its surface mount). Pair of metal tweezers perhaps?
I'm thinking right hand holding the tweezers (shorting the two pins), left hand to power it up at which stage it should complain about bad CMOS settings.

As for dismantling, FDD will need to be removed, screen has enough play in the cables to sit behind the laptop.

linuxlove
August 27th, 2013, 05:54 AM
Shorting those two pins worked. Thanks everyone; now I need to get this thing up and running.

SpidersWeb
August 27th, 2013, 11:49 AM
Shorting those two pins worked. Thanks everyone; now I need to get this thing up and running.
Awesome! I didn't expect you to be that quick about trying it, good work.