Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!math.fu-berlin.de!fauern!unido!cat!incom!orfeo!jrix!joachim
From: joachim@jrix.radig.de (Joachim Riedel)
Newsgroups: comp.os.coherent
Subject: Re: Searching: serial device driver for multiport-cards
Message-ID: <1991May09.110836.9481@jrix.radig.de>
Date: 9 May 91 11:08:36 GMT
References: <26748123@mailgsm.mendelson.com>
Organization: Joachim Riedel, Offenbach, West Germany
Lines: 49

root@mailgsm.mendelson.com (Geoffrey S. Mendelson) writes:

>>larger FIFO. I noticed that 9600 Baud on a 10 Mhz 286 is too fast,
>>but works on my 386/33 Micronics. But what to do if you want to use
>>a Traily with 19200 Baud ?
>>

>I have no trouble running an HP laserjet (IIP) at 19.2k using an interupt
>driven port.
Sure, 19200 Baud works, but I am thinking about the real CPS in the transfer.
With direct connection from my Laptop (10 Mhz 286) to a PC 386 with Telix,
I received files with rz. At 9600 Baud the rate was about 570 Bytes/s
with about 227 (!) errors during a transmission of 270 k. 4800 Baud works 
without errors (receiving !!!!, sending with sz is much better: 700 cps).
I want to say that Coherent is not able to get the 1400 cps that a
Traily in UUCPg-mode (S111=30) wants to send to the PC.

On my 386/33 Micronics Coherent is able to receive with rz and 9600 Baud about
850 cps without problems. But on my Interactive with 386/25 Micronics I got
about 950 cps receive rate same rz. Therefore I am thinking
about adding 16550 support to the standard serial driver to get 19200 Baud
at a reasonable cps-rate ( > 1200 cps). With it's  15 Bytes FIFO Coherent has
more time to get the received stuff before loosing characters.
I also don't want to buy a expansive intelligent board.
I will try to figure out how FAS 2.08 did it (Geoff, interest ? Also works
on ESIX !) and compare it with the existing Coherent driver.

>I think that the driver kit is worth the $40. Even if you only use it for an
>education. Unfortunately, I have seen no drivers come out of it yet. I am 
>hoping to see some soon. :-)  
I still have it but you need time to understand how a driver works (and also
the routines) before you start writing a device driver. Too many ugly things
can happen if there are errors in your code.
(The device driver kit is worth it's price. The manual is good and full of
information.)


>Geoffrey S. Mendelson          I've written and debugged almost eight thousand 
geoffrey@mendelson.com          LINES of C code under Coherent in the last two
>mwcbbs!mailgsm!geoffrey         months.  :-)                     
>(215) 242-8712                  And my wife still speaks to me!
----------------------------->   ^ let me know this trick, I need it

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