I admit a fondness for printed product information, so over the years I accumulated many data and application books and catalogs. During several moves, many went into recycle bins because the cost of transporting books seemed too high to justify. I still have a several data books but a few days ago thought about giving them the heave-ho into the paper-recycle bin. I held off–a lucky decision.
I’m working on a communication project for my town’s emergency operations command center that involves audio communications between two command-center radio operators. The final circuit will let the operators use headsets and choose their audio sources from among two radios and intercom communications. Think of a switching matrix and audio mixers and you get the idea. As part of my mic-preamp design I needed to find a data sheet for an older part. That’s when I picked up the almost-recycled National Semiconductor 1982 Linear Databook with its yellowed pages. I quickly found the IC’s information, pinout, and operating characteristics along with several application diagrams.
The data sheet exists online, too, but I didn’t want to print 25 pages. And online data sheets have a problem it’s easy to overlook: companies and people who post the information could disappear, disconnect, or delete information at any time. That leaves engineers who need older specifications for repair work, design updates, and so on, in the dark.
Aubrey Kagan, a long-distance friend, and author of “Excel by Example,” noted in an email today, “There was recently a complaint on 8052.com that Intel has taken down all the information on the 8051 family…”
To help remedy the ephemeral nature of product spec, Aubrey has started to scan and archive datasheets and now has 120 Gbytes of information on a USB hard drive. Tiger Direct advertises a 1 Tbyte (1000 Gbytes) USB hard drive for $90, so there’s room for a lot more information at low cost. And because the information exists on a personal device, Aubrey no longer depends on online access to out-of-print information. Aubrey plans to send me a copied drive with his scanned information and I’ll report more on what it contains in a month or so.
To put price in perspective, I found a used copy of National’s 1982 Linear Databook for sale ($US 17 + $US 6 for shipping) at AbeBooks.com. That’s about 40% of the cost of the 1 Tbyte drive. –Jon Titus