[stella] more keyboard nonsense

Subject: [stella] more keyboard nonsense
From: "John K. Harvey" <jkharvey@xxxxxxxxxxxxxxxxx>
Date: Mon, 06 Nov 2000 11:18:52 -0600
Hi, all.

Here's my next big question that's been bugging me recently:
For the keyboard controllers, according to the Stella Programmer's guide,
it says you need to wait 400 microseconds after sending to SWCHA to read
the INPT ports.  Has anyone written a small program to verify this?  How
many cycles is it in reality?
Doesn't it compute to:

1 sec / 1000000 microseconds times
400 microseconds = 0.0004 seconds

1194720 cycles per second times
0.0004 seconds = 

477.888 cycles = 6.288 scanlines?

Is it true?  Why the long wait?

	-John K. Harvey

Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/

Current Thread