Re: ECP port driver

[Robert Creager <robert@carolinecreager.com>]

Hey,

I'm hoping some fine person, with a slow box
(486/Pentium) and a 2.2 kernel can run a simple test. 
On the link below is a tarball of examples from the
Linux Device Drivers 2nd edition book.  Within said
tarball is a driver called short.  While it doesn't
run the parallel port in ECP mode, it should give a
rough idea of if the computer is capable of
downloading the data in a timely manner.  After
building and loading the module (by using make and
then short_load), execute the following statement:
time dd if=/dev/short0s bs=16 count=1000000 >
/dev/null

What this will do is execute 1 million 16 byte
transfers (using insb), trashing the results.  The
/dev/short0s is the device which uses the insb macro,
vs inb.  If the time of this command is less than 40
seconds, the computer might (should?) be able to keep
up.

For comparison, my AMD K6-2 500Mhz (roughly a Pentium
II), will execute the above in about 31 seconds, using
85% CPU (it's almost CPU bound, but not quite).

http://examples.oreilly.com/linuxdrive2/

---- Fraser Farrell <fraser@trilobytes.com.au> wrote:
> Robert (and list),
> 
> >Hmmm... 2.2 you say.  I was shooting for 2.4 - it
> >makes supporting devfs easier to do - no need for
> >IFDEFS.  Any particular reason you indicate 2.2?
> 
> The ECP port was introduced around the era of the
486; so I was
> thinking of a scenario where a 486/Pentium-class
computer sits outside
> in the cold & damp to run the Mark IV. Most of the
prebuilt distros
> with kernel 2.4 are a bit overwhelming for older
hardware. Or won't
> run at all.
> 
> OTOH you may need a powerful box with kernel 2.4 to
run the image
> analysis software.
> 
> 
> >If there are serious requests for 2.2, is anyone
> >willing to test some code on their platform? 
Although
> >I can grab another version of the kernel, my server
is
> >my playground, and I dislike rebooting often :-)
> 
> My server had its second reboot for this year two
days ago. A power
> cut which outlasted the UPS. I used this opportunity
to replace a
> noisy fan :)
> 
> 
> >Speaking of distribution specific, what
architectures
> >might someone use this on, and would that someone
be
> >willing to test some code?
> 
> Hmmm...of the boxes with ECP ports here; I can do
Redhat 6.1 (kernel
> 2.2.12) Mandrake 8.0 (kernel 2.4.something) or
Slackware 7. I've also
> got Redhat 7.1 but nowhere to install it yet. I
could also try it out
> with a couple of the mini-distros such as Dragon or
Phat.
> 
> What I don't have is a Mark IV (or something that
can simulate a Mark
> IV).
> 
> It may be worth developing a utility that can run
under DOS (or Linux)
> to simulate a Mark IV on any computer with an ECP
port. Including the
> output of known "test pattern" images for
verification of your setup
> and data analysis.
> 
> The ability to swap in a known-to-be-working
replacement is very
> helpful for troubleshooting. But having two Mark
IV's at every
> location probably isn't Tom's idea of effective
surveying! A simulator
> would also be useful for anyone without the camera
who wants to write
> control software for it.
> 
> Apologies if all this has been discussed before.
> 
> 
> 
> cheers,
> Fraser Farrell
> 
> 
> 
>