[rescue] Parallel ports [was Re: Slightly OT: ?Bad Cap Saga]

Joshua Boyd jdboyd at jdboyd.net
Thu Aug 21 12:11:56 CDT 2008

On Thu, Aug 21, 2008 at 05:04:52PM +0300, Geoffrey S. Mendelson wrote:

> Is it really that much of a problem? USB to parallel converters are sold
> in lots of places and they work fine with printers. (I know, you have the
> one that doesn't).

What they don't work with is software that insists on writing directly
to the parallel port, either by running as root and using inb and outb,
or be accessing a special port driver (/dev/port on linux, who knows
what on Windows).  And because it isn't as trivial to program, most such
software doesn't bother using IRQs or DMAs at all.  And even if someone
write a nice /dev/geekport driver for parallel ports under linux, you
probably would never be able to get people to switch to it.

Plus, at the end of all of that, the software never seems to port to
non-PC hardware with parallel ports, such as Sun workstations.

In case you can't tell, I hate this, and this is the cause of my
deathwish for parallel ports.  If you want to use a port with such
primitive means, then just dump a uC in there rather than abusing an
entire PC in such a manner.  If you need it to talk to PC sofware, then
use a USB port or RS232 port.

> Serial ports are a different story, but if you are using *NIX as the 
> operating system for the terminal emulator, or a Windows terminal program
> instead of Procomm* in a dos box, it should work fine with one of those
> PCI serial port cards. 

And anything that doesn't work should be howled about to the driver
writers and device manufactors, rather than pining for legacy serial

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