RE: Erasing DASD-decommission an AS400

Greetings:

My father was dealing with this in 1966, on a memory drum (800 lbs., 30
megabits [sic], $US 250,000 in current money). It had been used by the Air
Force and CIA in Saigon. Rotating armed guard, the whole parade.

Nobody knew how to reliably remove data from memory devices then, AND THEY
DON'T NOW. But the issue then was brand new.

Dad asked if it was OK to make the drum unusable. AF colonel (degree in
electrical engineering) said yes. Dad got a bottle of 2 molar nitric acid,
a chemically inert sponge, and a rubber glove. Took off the cover. Working
on the spin-away side at low speed, burned the recording media off right
down to the nickel. Said, "There, if you can get anything off it now, I
have another bottle."

AF colonel tested for quite a while using an oscilloscope (bits were BIG in
those days) and it flatlined all over. Finally, all the uniformed types
grinned broadly and headed for a party. Two weeks later Dad was
demonstrating his high-tech solution at Fort Dix, to a room full of people
wearing lots of little pieces of brightly colored silk and metal stars.

Use the method that would cost the thief more than the data is worth to
recover. If that isn't good enough, and it might not be, then do the simple
thing:  physically destroy the dadgummed drive. They just aren't that
expensive.

Darrell

Darrell A. Martin  -  630-754-2141
Manager, Computer Operations
dmartin@xxxxxxxxxxxxx