[Vm-dev] Mark and space parity

David T. Lewis lewis at mail.msen.com
Sat Sep 11 19:19:23 UTC 2010


On Sat, Sep 11, 2010 at 09:42:57AM -0400, Schwab,Wilhelm K wrote:
> 
> I ran across a device (barcode scanner) that uses space parity and dug into vm code to see if it was indeed going to be a problem.  This is not a debate on whether or not the designers of the device could have chosen something else: clearly they should have.  The question is whether our vms should be able to communicate with it, and they should where possible.
> 
> It is not clear whether Linux even supports space parity, though there are hints that recent kernels do so.  Windows certainly does support it.  Have any of you made the required changes and had success with it?  On which operating system(s)?
> 
> Bill

man 1 stty

This has nothing to do with the VM, and there is nothing wrong with
your barcode scanner. Just set your /dev/ttywhatever to ignore the
parity bit and you should be good to go. Space parity means that the
scanner is generating the parity bit, but it's alway zero so you should
ignore it.

Dave



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