25 Jul
2010
25 Jul
'10
11:10 a.m.
[USB dongles] work *remarkably* well with even old
printers [...]
but not any other parallel-port device, AFAIK.
But there's nothing inherent in the USB spec that prevents this as a
possibility, its simply the kind of USB dongle that people have built
to date, right? evidence is that software-wise it probably isn't,
'cos I am /guessing/
that a USB device can't present itself as a port on 0x378 on IRQ 7
etc.
I can't think of any obvious way of trapping I/O instructions on an 80x86
processor (which is essentially what you need for this). If you haf the
specs of whatever device you were trying to link up, then I guess you
could write drivers to use the USB adapter, but it would be a lot of work..
Incidentlaly, what do the USB-serial adapters do? I assume they don't
respond to acesses to the I/O ports conentionally used for PC serial
ports.
-tony