dlyons@Apple.COM (David Lyons) (10/08/89)
[David Brierley asks how to "deactivate" the reset key. Philip Stephens says you can't do it reliably, even though the Applesoft BASIC reference manual shows a method for trapping reset. Michael Pender disagrees and refers to a Nibble article showing how to trap reset in an Applesoft program.] Under Applesoft, you can trap reset *most* of the time. It will usually work, but it can't *always* work. Why? Imagine this: the Applesoft program is executing the statement X=5, and this is the first time the variable X has been referred to during the program--but there are lots of other variables, including some arrays, already used. The Applesoft interpreter has to -copy- all those arrays to a location 7 bytes higher in memory, to make room for X. Now, right in the middle of that copy, the user hits Reset. Ouch! The arrays are a big mess, and Applesoft will probably crash next time you try to access one of your arrays or create a new array. -- --Dave Lyons, Apple Computer, Inc. | DAL Systems AppleLink--Apple Edition: DAVE.LYONS | P.O. Box 875 America Online: Dave Lyons | Cupertino, CA 95015-0875 GEnie: D.LYONS2 or DAVE.LYONS CompuServe: 72177,3233 Internet/BITNET: dlyons@apple.com UUCP: ...!ames!apple!dlyons My opinions are my own, not Apple's.