Wiping the Hard Drive on an UltraLite

Thu, 15 Aug 91 17:08:40 MDT

If anyone is interested in seeing how to really toast your Ultralite (and how
to recover from it), read on!

A couple of friends of mine and I (well, actually my father) just got
NEC Ultralites, and decided to change the block size of the silicon
hard disk. We thought it would be better to make 512 byte blocks,
rather than 1K blocks, so we changed offset 00d to 01 (half of 02 for
1K blocks), and offset 016 to 10 (double 08 for 1K blocks, in hex).
This worked fine, and I would suggest that people change to this lower
setting, as I suspect it will further increase the efficiency. I'm new
to PCs, so if I'm wrong about this, please tell me so.

Anyway, not being satisfied with 512 bytes, we decided to try 256
bytes. We figured that offset 00d indicated one of two things. Either
it was: "number of blocks", or it was: 08 means 4K, 02 means 1K, 01
means 512 bytes, 00 means 256 bytes. If we had read the list digests,
rather than just the beginner's guide, we would have seen that it is
indeed "number of blocks" and not a lookup, but we didn't.

Dutifully we changed offset 00d to 00, and offset 016 to 20 (twice 10,
again, in hex). We then super rebooted with Ctrl-Alt-Del-Fn, and
nothing happened.

It wouldn't even boot off of the *ROM* drive!

We figured the best way to fix it was to kill the power to the silicon
hard disk. There appear to be 2 ways to accomplish this: One, pull
out the rechargable battery, and disconnect the leads from the 7 day
battery to the motherboard, or two, pull out the silicon hard disk
itself. Neither are as frightening as they sound, really.

You'll get a: "Battery fail has occurred" message, and the C drive will
be wiped.

The leads for the 7 day backup battery are located in the same
compartment as the ROM drive is. See spiffy figure 1.

|__ ___________ |
| | <ROM/ |removable| |
| _| <RAM | battery | |
|| <card slot ----------- |
|| "B:" |
| -----------|
|______ | |
| ROM | | silicon |
| hd | | hd |
|\"D:"/ | "C:" |
| -****> -----------|
| *------------------------ |
| *< 7d backup battery | |
| |_______________________| |

Spiffy Fig. 1

*** indicates wires from 7 day battery to motherboard

And I thought you couldn't toast hardware from software!

VaughAn Turner Internet: vturner@nmsu.edu
Networking/Workstation Support Box 30001, Dept. 3AT
Computer Center, Networking/WSC Las Cruces, New Mexico
New Mexico State University 88003-0001
Bitnet: vturner@nmsu UUCP: ...!ucbvax!nmsu.edu!vturner
Work: (505) 646-4244 FAX: (505) 646-5278 Home: (505) 522-3653

Home Address: 1115 Larry Drive Las Cruces, New Mexico 88001-5457

"...the first rule of engineering [is] to work with Earth's natural forces,
never against them."
"Earth" by David Brin