Re: [PARPORT] Aha !


grant@torque.net
Sat, 12 Sep 1998 13:26:42 -0400 (EDT)


> OK, but what is the PS2 mode?

Just another name for "bidirectional mode". Mode 2 in the epat driver.

> Are you referring to this in the linux
> environment? Grant mentioned that Syquest's drivers take advantage of
> some DOS idiosyncracies to adjust the timing but the linux side doesn't
> have the same options to do so and must make a best guess.

What I explained to you was that Shuttle's drivers (SyQuest has nothing
to with this) do performance tests when they load the driver. To do
so, they must write to a "safe" location on the disk. This is simply
impossible to do at the driver level in any Unix system. Drivers know
nothing about the filesystems. However, it would be a simple matter to write
a shell script that, given enough information, could load the pd driver
in all possible modes and with different delay factors and "optimise" the
settings for you.

Perhaps that's something that you'd care to develop and contribute to
the PARIDE project ?

> If Iomega has drivers that monitor for "buggy" chipsets, why can't
> the PARIDE suite follow suit?

Perhaps because Iomega has the resources to test their product against
all the possible ports ? If you'd like to fund me to work full time on
supporting PARIDE - and stock my lab with all the possible motherboards
out there, perhaps I could do something similar :-)

> That resembles in some fashion what I'm witnessing in my linux setup.
> When I ran cmp -l tests of my Sparq drive filenames against the source, 3
> fields with values like 134572 157 177 were returned. Grant pointed
> out that this appeared to indicate a 'sticky' bit

As I've explained elsewhere, this usually means a marginal cable or a
problem with the damping circuits at one end or the other.

> Hopefully this problem ONLY appears in linux and not other operating
> systems for the PP Sparq drive.

It has nothing to do with the operating system. The tuning parameters
are available precisely because there are a small number of systems where
the defaults don't work.

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Grant R. Guenther grant@torque.net
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