Re: [PARPORT] ppscsi/epst mode question (slow scanning w/ hp5200C)


Mark Thorp Duxbury (marktd@bellsouth.net)
Tue, 22 Jun 1999 19:28:54 -0400


Greetings,

"David Campbell" <campbell@gear.torque.net> wrote:

        You have "delay" set to 1 which *may* be not be necessary,
        older parallel ports have excessive capacitance which results
        in the output pin being sluggish. Given that you have EPP
        support then you should be able to reduce the delay. Further
        explanation requires some knowledge of electronics and first
        order filters. [you might get 25- 100% performance increase
        with delay=0, your milage may vary dependent on parallel
        port]

Yes, this did help. It brings the scan times down to a little over 3
min. (And yes, I do understand such things). Thanks, I appreciate the
help!

grant@torque.net wrote:

        If you load the driver with the "verbose=1" option, it will
        log a report about each of the port/mode combination it has
        tested. Included in that report are some numbers which might
        help to answer your question. Please send us this output.

I forgot to mention this in my first message, but I can't seem to get
ppscsi to log anything at all. I don't currently understand why. I get
all the other log messages I expect (from other processes etc.), but
nothing from ppscsi. Do I need to set something else still? If it
helps, "cat /proc/sys/kernel/printk" yields "6 4 1 7"; and syslog.conf
contains "*.* /dev/console", so I /think/ it should be logging just
about everything to the console. If I can get ppscsi to log stuff I'll
certainly send along the output.

grant@torque.net wrote:

        You also haven't mentioned anything about the machine you
        are using. There are some Thinkpad models, for instance,
        that appear to support EPP mode, but don't actually work
        (and only the actual data transfer test can detect this
        problem).

Sorry, I meant to include that my first message too, but somehow
neglected to actually type in the information before I sent it. The
machine in question is a PII-266 on an Intel AL440LX motherboard (sans
audio). This board uses an 82433LX (PCI/AGP), an 82371 (PCI/ISA/IDE),
and, probably of most use to you, a National PC97307 I/O controller
(which I think is functionally the same as the 87307). If it matters at
all, the BIOS revision is 4A4LL0X0.15A.0023.P18 (this is an OEM version
of I know not which Intel version - the machine is a Gateway). The
machine doesn't have a 'real' scsi port; the only 'scsi' device is the
HP5200 scanner. If any other information would be of help, just let me
know.

Thanks,
Mark

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