Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!quanta.eng.ohio-state.edu!czei
From: czei@quanta.eng.ohio-state.edu (Michael S. Czeiszperger)
Newsgroups: comp.sys.mac.hypercard
Subject: Problems with Apple's Hypercard serial XCMDs
Keywords: Apple, problems,hypercard,xcmd
Message-ID: <2416@quanta.eng.ohio-state.edu>
Date: 15 Jun 89 15:32:46 GMT
Organization: The Ohio State University Dept of Electrical Engineering
Lines: 56


I recently purchased Apple's serial communications kit, and thought it
would be useful to pass on my experience with the product. 

First, the overall design of the kit is very good.  I previously tried
some other public domain serial commands, and found that they weren't
as flexible for doing complicated serial communications stacks.  There
are more than just the "send" and "receive" types of commands, with
functions like CharsAvailable() to tell you how many chars are waiting
in the input queue, and others to tell you the current status of input
and output.

Unfortunately, the kit does not work as per the documentation. (We all
understand that I imply only that it doesn't work for me, not that it
would not work for everyone.  There may be something in my
configuration which is causing some or all of these problems.  I'm
using finder 6.1, system 6.0.2, and hypercard 1.2.1) There
are several bugs I've encountered which cripple the usefulness of the
product:

1.  Xon/Xoff still does not work on input or output.  I tried an earlier
version of the kit, and found that the Xon/Xoff did not work.  After
purchasing the latest version, 2.5b1, I've discovered that it still
does not work. Because of this, I have to set my input buffer to be
enormous to capture all incoming data without overflow.  On output, I
have to wait a second between lines so as to not overflow the other
end of the data stream.  

CAVEAT: I have not put a line monitor on the output to conclusively
prove that it is not working as per the Xon/Xoff protocol.  My only
test was with sending and receiving text from my stack, which did not
work correctly regardless of the configuration of the ports.  Input
data continually overflowed on small buffers, which would not happen
if the port was sending out Xoff's when the buffer was approaching
overflow.  Output data overflowed the target computer.  I tried both
sending large text fields to UNIX hosts, a C64, and a commercial
network.

2. It does not strip linefeeds from the incoming data stream,
regardless of whether that option is set or not.

3. It strips random characters from incoming data stream.  By this I
mean that it picks one character every time I boot the computer, and
deletes every instance of that character from my data stream.
Sometimes it is the letter "p".  Other times it is the letter "n".
And still others, the letter "g".  This wreaks havoc on my stacks,
making it impossible to make them work reliably.


I wonder how to communicate these problems to the Apple hypercard
people when I'm not a registered developer?  
-- 
Michael S. Czeiszperger | "...the average sea bass caught off the coast of
Systems Analyst         | Los Angeles contains three times your lifetime's
Ohio State University   | worth of toxins...", NBC News, 4/17/89
ARPA:czei@icarus.eng.ohio-state.edu  2015 Neil, Columbus, OH 43210 292-0161