Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!haven!grebyn!ckp
From: ckp@grebyn.com (Checkpoint Technologies)
Newsgroups: comp.sys.amiga
Subject: Re: DECnet for the Amiga
Message-ID: <12229@grebyn.com>
Date: 20 Jul 89 15:21:14 GMT
References: <735@orbit.UUCP> <791@medsys.UUCP>
Reply-To: ckp@grebyn.UUCP (Checkpoint Technologies)
Organization: Grebyn Corp., Vienna, VA, USA
Lines: 29

In article <791@medsys.UUCP> bbs@medsys.UUCP (BBS login) writes:
>
>Was this guy serious when he said the Amiga's serial port couldn't run above
>19,200 baud??? Call him back and ask if he's ever seen EMIT. It's PD, and
>allows two Amigas connected by serial cable to transfer files at 280,000 baud.
>Something like 292,000 baud (Bits Per Second Guys :-)) is the theoretical
>limit.... Granted the serial.device isn't as efficient as it could be, but
>it's not the hardware end that's at fault.
>
>-Wendell Dingus

Yes, it is the hardware's fault. The Amiga serial device does not
perform that well because the hardware does NOT provide for addition of
start and stop bits, and calculation of parity. The serial.device must
do this. Since it's a general purpose interface, it must provide these
features. EMIT is a very special purpose interface; it most likely
drives the hardware directly, and in a tight CPU bound loop polling the
serial interface registers. Now, you can get better performance from
serial.device by setting it to RAD_BOOGIE mode, in which it skips a lot
of the calculations (it only does 8 data bits, one stop bit, and no
parity in this mode), but it will never approach the 292000 baud limits
of the hardware.


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