Re: Joystick Devices

[wbaguhn@nyx10.cs.du.edu (Will Baguhn)]

In article <dempson-0608960110480001@dempson.actrix.gen.nz>,
David Empson <dempson@actrix.gen.nz> wrote:
>In article <4u3rdi$9kc@news.innet.com>, saw@camalott.com (Alan) wrote:
>
>>Hi all!
>>
>>dempson@actrix.gen.nz (David Empson) wrote:
>>
>>>It would be better to use the Macintosh version of the TouchWindow, which
>>>is an ADB peripheral.
>>
>>I might agree, except for those that want to use it on pre-GS models.
>
>Since I was talking about a GS/OS driver, this is a moot point.
>
>The problem with the Apple II version of the TouchWindow is that it
>requires a lot of intensive polling.  To get reasonable results means
>disabling interrupts, slowing the machine down to 1 MHz, and sitting in a
>loop polling it for up to three milliseconds, preferably twice to get
>decent readings for X and Y.  This should be done as often as possible.
>
>As you can see, this tends to affect the performance of the machine
>somewhat.  It is likely to kill AppleTalk connections if the TouchWindow
>is polled frequently enough.
>
>The same goes for using a joystick as a mouse.
>
>
>The advantage of the Mac TouchWindow would be that the ADB polling doesn't
>require slowing the machine down or locking out interrupts, so it won't
>have such a major impact.  (It should also take less time to do a poll.)
>
>-- 
>David Empson
>dempson@actrix.gen.nz
>Snail Mail: P.O. Box 27-103, Wellington, New Zealand

Would it be impossible to build a routine that doesn't require
interrupt lockout, doesn't require slowing the machine to 1 MHz,
and still gets fairly accurate readings?

[ Note: remember, we're working with Apple II's.  _Nothing_ is
impossible... just difficult, and... <ahem> interesting. ]

-- 
                                      --- Rev. SPQR (wbaguhn@nyx.net)