Path: utzoo!mnetor!uunet!husc6!bbn!uwmcsd1!ig!jade!ucbvax!hoser.berkeley.edu!bryce
From: bryce@hoser.berkeley.edu (Bryce Nesbitt)
Newsgroups: comp.sys.amiga
Subject: Re: HELP! (ummm, help?)
Message-ID: <22116@ucbvax.BERKELEY.EDU>
Date: 9 Dec 87 12:08:37 GMT
References: <549@zehntel.UUCP>
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: University of California at Berkeley
Lines: 28
Keywords: bitpad, serial device, dpaint

In article <549@zehntel.UUCP> donw@zehntel.UUCP (Don White) writes:
<
<          I have been given a bitpad (i.e. digitizing tablet)...
<	...It works, but something is not right.
<
<       ...I can use the bitpad to operate workbench, but when I try to 
<     start Dpaint it barfs intensely. The cursor slows way down for a 
<     while, then it speeds up and starts zipping all over the screen...
<
<       ...I don't know where to find the problem. I've tried twiddling
<     the task priorities, but it doesn't make any difference. Is DoIO()
<     too slow? Is Dpaint doing some busy waits?
<     I multitask this
<     program by 'run'ning it from a CLI. 

Dpaint *is* doing busy waits while drawing.  Your program probably needs
to SetTaskPri() itself to 19 or 20.  The input.device itself runs
at 20. (too low, really.  Those system tasks should jump into the 
hundreds)

DoIo() is not too slow, but 
remember, *always* do a query of the serial device to see how
many bytes are available to read before you do the read.

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