Make a PC Look Like a Firewire or USB Drive?

buckinm asks: "Here's the problem: I have a Windows laptop that I use for work. When I'm at home though, I much rather use my Mac. Since we use Cisco's VPN client at work, I can't mount the drives on the PC from the Mac. What I'd like to know, is there any software out there that would make the PC act like a Firewire or USB drive? I'd want to be able to mount it read/write. I know I could do some sort of rsync of thing when not connected to the VPN, but that seems like too much trouble. I wouldn't be against writing something like that, if I could get some idea of what is required to listen / respond to traffic on the Firewire or USB ports."

Comments

Possible, I think

[MBCook]

I see no reason that it shouldn't be possible. Macs can do this. You boot them while holding "F" or "D" or "Command-F" or "Command-D" or something. They sit there and act like a firewire disk. I think you can even access the CD drive in them.

As for the PC side, I don't know. It's obviously possible, but I haven't heard of it. The Tinkerer in me says make a switch that disconnects the HD from the computer and connects it to a IDE->Firewire adaptor you hide in the case. Switch in one position it's a normal computer. Switch in the other it's a firewire disk.

Good luck.

Re:Possible, I think

[Joseph Vigneau]

Because the motherboard manufacturer's only control the motherboard, and in some cases either the video card or the CPU, not the memory, hard drive, sound card, TV tuner card, Firewire card, network card or pretty much anything else that Apple keeps tightly under their control.

More and more motherboards have this stuff on board, particularly Firewire and USB controllers. With a smarter BIOS (maybe even LinuxBIOS), those manufacturers could provide a service similar to Apple's Target Disk Mode.

FWIW, Apple doesn't have tight control over drives and memory; these are commonly swapped out with commodity parts with higher capacity by end users.

And, as someone else mentioned here, there's at least one PC laptop manufacturer that has this feature.

ive only used firewire 3 times in my life but...

[ForestGrump]

the firewire interface has a tcp/ip stack.

Same thing, for Pocket PCs?

[Kris_J]

Is there a program that will make my Pocket PC (Asus 716) behave like a normal USB drive so I can copy stuff on and off of it without needing the ActiveSync app installed?

FireWire? Likely. USB? I doubt it.

[veliath]

FireWire host-controllers in PCs are symmetric as far as I know, so you could theoretically have a PC behave like a FireWire drive (i.e. speak SBP2). The protocol itself is a form of RDMA - which means FireWire controllers export their hosts as addressable 48bit memory ranges. Should be symmetric.

USB host-controller in PCs are different. In USB, only the host-controller can bus-master - i.e. initiate transactions on the USB bus - no other device on the bus can. I believe this is specified in the protocol itself. The protocol allows for a smart host-controller and dumb devices. One master and the rest slaves.

This might become clearer if you examine the terminology. The ports closest to the host-controller are said to belong to the "root hub". USB provides for a tree architecture, rooted at the host-controller's ports.

This means that you cannot connect two PCs back-back through their USB ports and say run PPP over them. AFAIK host-controllers in PCs do not have a slave mode that they can be switched to.

The PC emulating a hard-disk has to be able to become a slave to show up as a device.

veliath