🚀 go-pugleaf

>From: dubois@uwmacc.UUCP (Paul DuBois)
>[...] It's not so easy to tell, when there
>aren't any application windows, that a DA window has come up (so that
>Close should be enabled) or the last DA has gone away (so that Close
>should be disabled).

I suspect that there are a lot of applications out there that completely
reconstruct their menus whenever a mouse click in the menu bar is
received.  In particular I think MacWrite does this, because it takes
extraordinarily long (about a second?) from the mouse click till the
menu falls down.  It might be that most of the time is spent in the
AddResMenu call for the Font menu.

A different obeservation regarding the "Close" item in most File menus
is that I never use them.  I always click the close box.  I believe this
is true for most, even very novice Mac users: the close box is about the
first shorthand you learn to use, and soon you'll forget it has an alias
as a menu item...  Therefore it would not be a big loss if your Close
menu item were deactivated when a DA window was on top.  In fact a DA
might choose to have a window without a close box, which makes your
decision to activate the Close menu item equally wrong.  I believe that
in principle, an application cannot know enough about a DA to know which
menu items to (de)activate; the only rule is that the Edit menu should
have Undo, Cut, Copy, Paste and Clear, even though not all DA's actually
respond to these (the highlighted Undo is particularly bad, since it
makes novice users believe that they can Undo their actions).

Straying away further from the subject, often I miss a *keyboard*
equivalent to clicking the close box.  Now that Standard File Dialogs
can be operated completely from the keyboard, and so many other
operations have keyboard shortcuts, it is annoying to have to grab the
mouse to close a window.

And, finally, on keyboard equivalents: when a DA is active, key presses
are generally processed by the DA, not by the application.  This means
that the application, if it wants to be super-correct, should remove the
shortcuts from its menus -- *except* ^Z, ^X, ^C, ^V for the edit menu!
So here you have a reason why you *do* want to detect wheter a DA is
active, even if you don't want to activate Close, and we're back to the
original question: how to detect it and when to changes the menus?
The proper thing to do in my opinion is to check continuously in the
main loop, but update the menus only when a change is detected.
-- 
	Guido van Rossum, CWI, Amsterdam <guido@mcvax.uucp>

Organization : California Institute of Technology
Keywords: serial, audio

I would like to use the serial port with an external clock for some hardware
I am making.  (An audio digitizer running at ~400 kbaud.  The final cost
should be under $20.  I will post the plans to the net if anyone is
interested after I have finished it.)

The serial driver section in my copy of Inside Macintosh (Phone book version)
does not tell me how to use the external clock, nor does it tell me how
to change the clocking frequency from whatever it usually is (16 times
the baud rate, I think) to equal the baud rate.

I remember that when the Mac came out the "virtual slot" concept gave a
maximum data rate of ~1 Mbaud with external clocking, ~400 kbaud with
internal clocking, but IM does not tell us how.


			David Palmer
			palmer@cit-vax.edu
			...seismo!cit-vax!palmer

	I've followed you, talked to your neighbours, tapped your phone,
	and even shot at you to see how you would react.  From my observations
	I have come to one irrefutable conclusion: You are Paranoid.

In article <1120@cit-vax.Caltech.Edu> palmer@cit-vax.UUCP (David Palmer) writes:
>...
>I would like to use the serial port with an external clock for some hardware
>I am making...
>The serial driver section in my copy of Inside Macintosh (Phone book version)
>does not tell me how to use the external clock, nor does it tell me how
>to change the clocking frequency from whatever it usually is (16 times
>the baud rate, I think) to equal the baud rate.
The serial driver only supports asynchronous communications at one of a fixed
set of baud rates.  In order to communicate at 400KB, you will need to use
one of the synchronous communication modes of the Z8530 SCC hardware in the
Mac (documented in the hardware chapter).  You will have to write your own
driver software to accomplish this, and access the hardware directly.
In addition to Inside Mac, you will need the Z8530 technical reference,
available from the manufacturer.

Although the Z8530 supports a large number of communications modes
(async, bisync, HDLC, SDLC, etc), the serial driver was only intended
to support standard async, not any of the fancier stuff.  I'm not sure
the Z8530 even supports async above 56KB.  AppleTalk uses one of the
synchronous modes and has its own low-level device driver.



-- 
David Goldsmith
Apple Computer, Inc.
MacApp Group

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