100ma is far too weak for any kind of USB HD, buts totaly fine for joysticks, keyboard/mice, USB Flash card readers, anything that does not have any motors really.
If you wanted a compact solution that does not suck the batteries dry fast, I'm thinking 2 3v Coin cells used in watches could be used for 6v, then steped down to 5v. Current draw may be an issue still, but nobody will be dragging a whole 3.5" HD-in-a-USB box. (it will be a 1.8" self-powered HD or something)
These early prototypes are just thrown together. Someone will eventually make a full custom design that really rocks. (Small, ports of all kinds, self-powered, TV-out, perhaps even JTAG)
If you wanted a compact solution that does not suck the batteries dry fast, I'm thinking 2 3v Coin cells used in watches could be used for 6v, then steped down to 5v. Current draw may be an issue still, but nobody will be dragging a whole 3.5" HD-in-a-USB box. (it will be a 1.8" self-powered HD or something)
These early prototypes are just thrown together. Someone will eventually make a full custom design that really rocks. (Small, ports of all kinds, self-powered, TV-out, perhaps even JTAG)
