[comp.sys.apollo] Screen blanking

te07+@ANDREW.CMU.EDU (Tom Epperly) (05/28/87)

I am new to programming with the apollo so bear with me.  I would like to
write a program to blank the screen if no "key or mouse button" is pressed in
a specified length of time.  The current system screen blanker does not blank
the screen since we have a digital clock running.  I am assuming that the
system screen blanker looks for both graphic events and keyboard events.
Does anyone have any ideas?

If I could locate the display managers screen structure, I could add an event
handler to that screen, but I don't know how to get its location.  Any
suggestions, alternatives are welcome.

Tom Epperly
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ganek@apollo.uucp (Dan Ganek) (06/10/87)

te07+@ANDREW.CMU.EDU (Tom Epperly) writes:

> I am new to programming with the apollo so bear with me.  I would like to
> write a program to blank the screen if no "key or mouse button" is pressed in
> a specified length of time.  The current system screen blanker does not blank
> the screen since we have a digital clock running.  I am assuming that the
> system screen blanker looks for both graphic events and keyboard events.
> Does anyone have any ideas?

> If I could locate the display managers screen structure, I could add an event
> handler to that screen, but I don't know how to get its location.  Any
> suggestions, alternatives are welcome.


I have some good news and some bad news.

Bad news - it's not that the screen blanker doesn't work; it's that some
graphics routines are lazy and always turn video on whenever they do
output. Writing a program to blank the screen wouldn't help since
as soon as the clock program changed the screen it would cause the 
screen to unblank.

Good news - fixed in SR9.6. We went through and found all the routines
that played with the video bit. With SR9.6 video is turned on only when
there is input or when the DM changes the screen configuration. e.g. 
putting up an alarmer window.

/dan