On 3/14/07, Chuck Guzis <cclist at sydex.com> wrote: <AOL> Me, too. </AOL> For me, at least, the difference is that a word processor or credit card terminal or a gas pump, or whatever, does what it does and is difficult to have it do something it was not designed to do. If it were possible to get developer-level documentation on the internals of said embedded devices, that might be something different entirely. The one class of devices like this that _is_ thoroughly explored is Internet/e-mail appliances like the Audrey, the WebPal, the iOpener, etc. Many of these, of course, are just Intel PCs with a UNIXy OS in FLASH ROM, but at least they are inexpensive enough and powerful enough to attract attention from the contemporary hardware hacker community. Older devices, while interesting in their own right, aren't as easy to come by, or, prior to the advertiser/subscription business model, were paid for by the end user, not heavily subsidized. ISTR IOpeners were costing the company $400 each, but were marketed at $99 (later $99 plus a mandatory 4 month sub.) For a 200MHz PC w/USB, 16MB Flash, 800x600 LCD, single-DC-voltage power (19VDC), $99 was a *scorching* price, so lots of hackers picked them up and figured out how to dump the OS and replace it with Linux or Windows (yes... people _did_ put Windows98 on them). For your money, you get a nice little toy that's easy to reverse engineer, and when you do, the machine becomes quite useful for a variety of applications. A used credit card terminal for $20 (or whatever the going rate is) can still be turned into something else, but it's not going to capture the attention of an army of curious hackers. I guess the other thing is... for as much work as it would be to delve the secrets of a credit card terminal, I can whip together an LCD display and a microcontroller for a few bucks and have 100% control over its innards. If I don't care to start from scratch, I can begin with any number of Atmel/LCD projects already out there (and I've done just that recently). At that point, the advantage of an existing CC terminal diminishes rapidly. It still has the benefit of being mass produced and potentially abundant, but anyone can order an ATtiny2313 for a couple of bucks and hang a 2x20 text LCD or a 128x64 graphic LCD off it and make it display some sensor input or whatever. The CC terminal has to have some pretty cool stuff in there to pull into the lead for a hardware project - I'd most likely gut the LCD and possibly keep the plastic case for some other project than hack the microcontroller that's already in there, and that's presuming it's not a mask-programmed part and that I can reflash the chip. So while I might not turn down a box of embedded devices like a credit card terminal, hacking a lone terminal isn't as appealing as building a similar device from scratch and knowing exactly how that new device works. As I said, though, having developers' docs might tip the balance, but the chances of that are rather low. -ethan