Backchannel on OSX 10.4

[Michael R Sweet]

keens312 wrote:
> Hi Michael,
> 
> On 10.4, the usb backchannel is one-way, host->printer, is this true?

Yes, although it isn't called a backchannel in that direction...

> To receive printer feedback information on 10.4, developers have to write a own bi-di usb backend to replace Apple's standard one.
> 
> Or write a USB IOKit to do the IPC with CUPS filter.
> 
> What's the best solution for bachchannel on 10.4?

You want to look at doing a USB class driver - Apple DTS can supply
you with the sample code.  The USB class driver allows you to add a
"read" function to the Apple standard class driver - basically you
just write/replace the parts you need to.

-- 
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Michael R Sweet                        Senior Printing System Engineer