Path: utzoo!attcan!uunet!mcvax!enea!kth!draken!tut!santra!kampi!jmunkki
From: jmunkki@kampi.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Text Drawing at speeds in excess of 1200baud
Message-ID: <18937@santra.UUCP>
Date: 24 Jan 89 09:07:03 GMT
References: <2220@uokmax.UUCP> <568029@vaxa.uwa.oz> <9000@pasteur.Berkeley.EDU>
Sender: news@santra.UUCP
Reply-To: jmunkki@kampi.UUCP (Juri Munkki)
Organization: Helsinki University of Technology, Finland
Lines: 30

In article <9000@pasteur.Berkeley.EDU> dean@xcssun.Berkeley.EDU (R. Drew Dean) writes:
>In article <568029@vaxa.uwa.oz> d_volaric@vaxa.uwa.oz writes:
>>I don't know if you are doing so already, but I would buffer the text coming
>>from the serial port and then use DrawText to draw a bunch of characters
>>at the same time. I doubt whether DrawText of say, 10 characters is slower
>>that 10 characters at 2400 baud. I would check the buffer every few ticks
>
>There's one problem with this approach: it's ugly. (As first pointed out
>to me by a friend, when I suggested the same thing :-))  If you want to
>see what it looks like, check out Miniterm (I have version 2.9.1) at 2400
>baud.  You'll see it jerk.  Then look at VersaTerm.  It's smooth, just like
>a real VT-100 is.  I realize that it's probably not necessary to draw each
>character one at a time as they come in, but DrawText needs to be called
>with a small (ie. 2 or 3) number of characters each time, if you want the
>text to flow smoothly.

Hmmm... The problem isn't that the programs draw several characters at a
time, but that they wait between the calls. My program looks very smooth and
it usually draws about 80 chars at a time when used at 9600 or 19200.

Look at the serial buffer, read all the characters that are already there
and blast them to the screen. My program has two serial buffers. One for
the drivers (normally about 8KB) and the other for FSRead (about 80 bytes).

VersaTerm seems to draw the same way my program does.

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|     Juri Munkki jmunkki@hut.fi  jmunkki@fingate.bitnet        I Want   Ne   |
|     Helsinki University of Technology Computing Centre        My Own   XT   |
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