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From: pnakada@oracle.com (Paul Nakada)
Newsgroups: comp.sys.apple
Subject: Re: MNP level 5 (really: handling 9600 baud at 1 Mhz)
Message-ID: <PNAKADA.90Mar1114843@pnakada.oracle.com>
Date: 1 Mar 90 19:53:10 GMT
References: <9002281406.AA15912@masig2.ocean.fsu.edu> <2671@uwm.edu>
	<1990Mar1.103507.13022@spectre.ccsf.caltech.edu>
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In-reply-to: toddpw@tybalt.caltech.edu's message of 1 Mar 90 10:35:07 GMT

In article <1990Mar1.103507.13022@spectre.ccsf.caltech.edu> toddpw@tybalt.caltech.edu (Todd P. Whitesel) writes:

   jeffd@csd4.csd.uwm.edu (Jeffrey Alan Ding) writes:

   >  At 9600 baud, the computer chokes.  I send
   >it an AT command and I don't even get the OK signal back.  I tried
   >several term programs including Kermit, Talk is Cheap, Zlink, and Mousetalk.
   >Talk is Cheap was the fastest in scrolling.  No program worked at 9600 baud.

   >My computer is only running at 1 MHz.

[ stuff deleted ]

   Still, you should be able to handle 9600 baud because even at full rate
   reception over half of the //c's CPU time is left over -unless- your
   term program sucks and it's interrupt handler takes forever, which I
   really doubt. It's probably the //c's firmware.

   Todd Whitesel
   toddpw @ tybalt.caltech.edu

I had the same problem...  I have a feeling that the //c interrupt
firmware is too slow for 9600 bps..  I had the exact same problems
with a 9600 bps MNP 6 modem.  The problem went away when I got a 8 Mhz
Zip Chip, even at 19.2K bps..  All of this was true with proterm,
zlink, and kermit.  

-Paul 
pnakada@oracle.com
nakada@husc4.harvard.edu