[sane-devel] USB to parallel port converters

[Steve Underwood]

Neil Youngman wrote:
> I would be surprised if the adapter didn't support bidirectional ECP/EPP 
> modes, but I could always be wrong. It was advertised as a printer adapter. 
> There may be some modes required for scanners that it doesn't support, 
> however I suspect that the problem is more likely to be SANE assuming that 
> parallel port devices are only found on parallel ports and not on USB. Does 
> anyone know if this is the case?
>
> Neil
>
>   
Then be prepared to be surprised. A USB serial gadget is a close 
emulation of a traditional serial port. A USB parallel gadget is not 
even vaguely similar to a traditional parallel port. The huge latency of 
USB means it would be impractical for it to work in the same way. This 
is a huge pain for a wide range of industrial gadgets, embedded 
development tools, and other gizmos which only work with a PC's parallel 
port. Even if you try written a custom for the USB gadget, the latency 
makes it useless for almost anything.

Regards,
Steve