From: Gregg C Levine (
Date: Tue Mar 11 2003 - 19:43:24 EST

  • Next message: Tim Waugh: "Re: [PARPORT] ECP and DMA"

    Hello from Gregg C Levine
    What sort of "some home brewed hardware", Mark, is this? That's the
    principal reason behind my rejoining this list. I am planning on designing
    such hardware, (data upload, and data display), during coming months, and I
    want to actually solicit some advice.

    For example does a generic library exist for the Parport? And where would I
    be able to find it? Also, I'd be interested in finding out more about this
    problem that you are relating, as I suspect more of us would. If at all
    possible, folks please post such replies directly to this address, and thus
    to the list, I do not want to flood the list, unless necessary.
    Gregg C Levine or
    "May the Force be with you!"

    ----- Original Message -----
    From: "mark anderson" <>
    To: <>
    Sent: Monday, March 10, 2003 7:49 PM
    Subject: [PARPORT] ECP and DMA

    > I'm playing with some home brewed hardware to upload data into
    > my linux box. With EPP I'm getting about .5 MBytes/sec. I see
    > claims that 2M should be the upper limit. Is there a specific
    > mode that runs this fast (EPP/ECP/???). I can make my hardware
    > do whatever protocol and timing makes things fastest.
    > In a related speed issue, I'd like to use the DMA channel. However,
    > I've found a note in the parport bug list (Suse, 2.4.10-4.GB):
    > o parport_pc_ecp_read_block_pio() is broken. parport will revert to the
    > software-driven mode in ieee1284_ops.c
    > Is this telling me that DMA reads under ECP are broken? As I read
    > various parallel port documents I'm lead to believe that only ECP
    > supports DMA.
    > Any thoughts would be appreciated. Thanks.
    > --mark
    > -- To unsubscribe, send mail to: --
    > -- with the single word "unsubscribe" in the body of the message. --

    -- To unsubscribe, send mail to: --
    -- with the single word "unsubscribe" in the body of the message. --

    This archive was generated by hypermail 2b29 : Tue Mar 11 2003 - 19:49:49 EST