Date: Wed, 30 May 2001 09:26:41 -0400 (EDT) From: Paul LaFollette <lafollet@netaxs.com> To: questions@FreeBSD.org Subject: ppi.c and PERIPH_1284 questions Message-ID: <200105301326.JAA05380@unix3.netaxs.com>
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Hi, I am trying to infer (i.e. reverse engineer) the control sequences used by a device that connects to an EPP/ECP port. I want to log the transactions between a PC running Gatesware and the peripheral from the evil-company-that-wont-provide-programming-information. I propose to do the following: Grab an old PC, stick in two EPP/ECP ports (call them port-PC and port-S). Connect port-PC to the Gatesware machine using a cable wired as suggested in the ppi.c file. Hook up port -S to the peripheral with a standard printer cable. Grab everythiing coming from port-PC and send it to port-S, and vice versa. Log it all along the way. I have several questions/concerns: o) Has someone already done this? Is there code floating around somewhere that I can use or modify? i) I am guessing that I want to configure port-PC with the options PERIPH_1284 asserted. What about port-S? If port-S should NOT have this option, then is there an easy way to assert the option for ppi0 and not for ppi1? (easy means without hacking the ppi.c source.) ii) Do I even want to use ppi for port-S? Or do I want to use a different device? iii) When ppi is in PERIPH_1284 mode, do read and write work (in addition to? instead of? ioctl)? From looking at the driver, it looks like they do. iv) Is there any documentation for ppi and PERIPH_1284 beyond what I have found in ppi.c and LINT? v) Will this idea even work? Am I wasting my time? vi) Do I need to worry about getting port-PC into "input" mode before I attach the cable? Can I damage the ports if both are in "output" mode when I hook them together? vii) What have I forgotten to ask? Thanks for any sugestions you can offer. At the moment I am unsubscribed from "questions" so email would be appreciated. Feel free to forward to a more appropriate list if I have picked the wrong one. Paul LaFollette CIS Dept. Temple University lafollet@netaxs.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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