Re: USB scanners?

Matto Marjanovic (maddog@mir.com)
Wed, 2 Dec 1998 03:16:49 -0500 (EST)

>From: David Mosberger-Tang <davidm@mostang.com>
>
>It occurred to me that this whole boring debate about parallel-port
>scanners and the lack of support may soon disappear as a result of USB
>picking up in popularity. Maybe we should focus on USB support? It

I think I missed any recent debate --- just discovered this weekend that
due to a unknown multi-week mailer snafu, I got unsubscribed from this
list, and have missed about 2 weeks of messages, among other things.

Anyhow, to chime in, I think USB per se is not really a SANE issue.
SANE supports SCSI scanners on pretty much every unixish/posixish OS
which has a "generic SCSI" interface. And those are standard,
general, but OS-specific mechanisms written by someone else. The
same goes for SANE's digital camera backends which use the ubiquitous
standard serial ports. In both cases, a low-overhead system API
exists for pushing data around whatever medium.

This might be feasible soon with parallel ports, at least under Linux.
Anyone know what the "parport" driver in the newer kernels does?

[my minor rant on parallel ports moved to end...]

I'm not sure how to "focus on USB" if I have no USB equipment.
What is the state of general USB support in various OS's? As soon as
kernel access to the USB bus exists, and someone has a USB scanner, I
imagine it'll be the familiar story of writing a complicated backend
which makes up for the deficiencies of retarded scanner firmware,
which is coupled to the machine by a bit of "sanei-usb.h" glue code.
(I don't know anything about the USB bus, but I figure it can't be
too far away from "send a command to a device, receive a reply".)

Then the job for the rest of us is just to be vigilant and make sure
the code and its coupling to the system are neat and respectable.

-matt m.

and, here's the rant:

The parallel port is still relatively useless, though, because:
a) a low-overhead system API is pretty scarce, if it exists at all
b) what else has a parallel-port besides a PC? you can find SCSI
and serial ports on Sparc's, PowerPC's, SGI's, etc...
And, if the port needs to be driven in some screwy bit-by-bit way
like the B/W QuickCam, let a properly psychotic hacker write a
backend, and label it with the warning "Why would you want to do this
to your happy, efficient OS? Make a stand! Throw that junk scanner away."
(Winmodems are cheap and plentiful now, too, but you are a *dumb ass*
who is perpetuating bad engineering if you buy one, plain and simple.)

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