[mdlug] External Floppy Drive

[Aaron Kulkis]

Peter Bart wrote:
> On Mon, 2009-02-23 at 21:30 -0500, Michael Rudas wrote:
>> --- Peter Bart wrote:
>>
>>> I'm in need of an external floppy drive; and taking Rays advice on not
>>> letting the drive suck power from USB; I went looking. Just quickly
>>> looking in a few places, all seem to be powered via USB. Is this because
>>> the power requirements are not as large a hard drive and could safely be
>>> powered by the USB port, or should I seriously go looking? I would be
>>> using this at home, so power availability is not an issue.
>> Basically, ALL USB-external floppy drives are port-powered--I've never
>> seen one with external power--the power requirements of a 3.5-inch
>> floppy drive are less than the 2.5 watts (5V at 500mA) that a USB port
>> can source.  As Aaron pointed out, a powered hub would reduce draw
>> from the PC--in fact, a USB 1.1 hub is fast enough (floppy drives are
>> SLOW)--and you might even have one around the house...
>>
> 
> 	I thought that might be the case. I was able to dig up the power
> consumption of a Lacie external floppy, but nothing to compare it to.
> Such as the hard drives Ray was talking about. You're right, I have
> several Belkin powered usb hubs around, not sure if they're 1.1 or more
> recent. As you point out it's moot anyway. Thanks for weighing in. I've
> got one on order

1.1 is OLLLLLD in USB years, (about 1/100th the speed of USB 2.0),
but it still has more bandwidth available than a stack of floppies.
(Consider this: USB 1.1 is capable of transmitting 1 MB in about
1/4 of a second.  A floppy takes around 90 - 120 seconds to
send or receive 1 MB of traffic).

> <http://stores.channeladvisor.com/LenovoOutlet/Items/ca05k9276?sck=8972224&caSKU=ca05k9276&caTitle=ThinkPlus%20USB%20Portable%20Diskette%20Drive>. 
> 	I was wondering about a usb/serial adapter, you might know the answer?
> If I plug the floppy into the powered usb hub, then use a usb to serial
> adapter to get to a computer w/o a usb port, would that work? Just idly
> curious.

It should.
But realize that USB assumes a Computer (master)/peripheral (slave)
model.  Firewire (IEEE 1394) is peer-to-peer.   However,
IEEE 1394 ports are also a security hazard, because they
the interface definition allows DMA (direct memory access)
to be initiated by an external device, without coordination
form the host where the memory is located -- thus, data
can both be copied, and or forced into a host's memory
to/from a peripheral without any permission from the host.

> 
> Best Regards,