Date: Thu, 21 Feb 2002 16:20:13 +0800 From: Raymond <[EMAIL PROTECTED]> Subject: Re: [LIB] Some answers please?
At 11:36 PM 20/02/2002 -0800, you wrote: >Date: Thu, 21 Feb 2002 07:27:52 >From: "neil barnes" <[EMAIL PROTECTED]> >Subject: Re: [LIB] Some answers please? > >>Date: Thu, 21 Feb 2002 01:27:31 -0500 >>From: David VanHorn <[EMAIL PROTECTED]> >>Subject: Re: [LIB] Some answers please? >> >> >>> >>>I haven't looked at the IRDA spec, so I'm guessing here...but I can't >>>imagine that *anyone* (even MS) is dumb enough to implement a serial link >>>without flow control of some sort. >> >>They aren't >> >> >>>Of course, whether the IRDA interface implements those things to the >>>driver is another question :) >> >>They do. >> >>However, not exactly in the way you think, >>You don't see the handshake directly from the remote device, it's not >>necessary. You see handshake from the local IRDA dongle. It's buffers are >>what you must not overflow, and it must not overflow yours. >> >>The end result is the same, you put data into the dongle at rate X, it >>travels between dongles at rate Y, and from the far dongle to the device at >>rate Z. Your throughput will not be greater than the lowest rate of the >>three, and not much less, if X and Y are reasonably high. Y cannot be less >>than 9600. X and Z can be anything from 300-115200 (typically) > >You mistake me! That's exactly the way I would have implemented it - the software >interface to each end only cares whether the hardware can accept data. What the other >end is doing is immaterial, as is the mechanism for getting the data there. >Maintaining a channel for state information which rarely changes is at best, wasteful >of resources. > >This being so - an IRDA to serial adaptor should be a fairly trivial device: IR >transmitter and receiver (and shaping circuits), some buffer memory, a standard >serial interface, and a small processor to keep it all in step. Probably fabricated >on a single chip. ... exactly what I said in that essay ages ago (except for the fact that if there was no point having those handshaking lines, why bother having them in a standard serial port? Answer is that every now and again those lines DO change! But thats trodden ground already). - Raymond --- /~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\ | | "Does fuzzy logic tickle?" | | ___ | "My HDD has no reverse. How do I backup?" | | /__/ +-------------------------------------------| | / \ a y b o t | [EMAIL PROTECTED] | | | HTTP://www.raybot.net | | ICQ: 31756092 | Need help? Visit #Windows98 on DALNet! | \~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~/ ************************************************************** http://libretto.basiclink.com - Libretto mailing list http://libretto.basiclink.com/archive - Archives http://www.picante.com/~gtaylor/portable/faq.html - FAQ -------TO UNSUBSCRIBE------- Reply to any of the list messages. The reply mail should be addressed to: [EMAIL PROTECTED] - Then replace any text on the message's subject line: cmd:unsubscribe --------TO UNSUBSCRIBE DIGEST------ Do above but with this on subject line: cmd:unsubscribe digest **************************************************************
