atari email archive

a collection of messages sent at Atari from 1983 to 1992.


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	As with any computer program, nothing is immune to enhancements.
The 'basic computer' of a week or so ago has become an 'extended basic
computer'.  Here is the new, improved documentation (believe it or not!)

	Modify your file to include:
		$ GOSUB :== @sys$sysdevice:[]gosub
		$ RETURN :== @sys$sysdevice:[]return
		$ GOBACK :== @sys$sysdevice:[]goback
		$ WHERE :== @sys$sysdevice:[]where
... and you will have these four words defined.  You can use any word you
like (an example is STACK instead of WHERE) but the right sides must be the
same.  These will NOT be installed on a system-wide basis because there is
still hope that GOSUB and RETURN may become legal, real words in command
procedures, and we would then have to pick something else for these things.

	GOSUB works like set default (that's what it is for), but it saves
the current default (device included) on a symbolic stack.  Return does the
obvious thing.  Gosub takes one argument, the place to gosub to.  (what
you would feed set default).  If you don't supply it, you will be prompted.
Return reminds you a) where you are returning to, or b) that you blew it
and don't have anywhere to return to; in which case it sets you up in your
"login directory", which has the permanent logical name SYS$LOGIN .

	GOBACK is intended for those people who can't make up their mind (like
Owen and me) and shuttle back and forth between the directories.  GOBACK is
for when you did too many returns; another word for GOBACK might be UNRETURN.

	WHERE lets you know what kind of a mess you are in.  Specifically, it
lists, in order, all the places you've "visited".  It points out (quite
literally) where you are (your current default directory, no matter HOW you
got there (gosub, set default, return, goback) and where you would go if you
used the GOBACK and RETURN verbs (it assumes you would use those words).

	It should be mentioned that your current default is saved, when you
do a GOSUB, a RETURN, or a GOBACK; so that SET DEFAULT is still consistent
with the meaning of all these words.  The best way to understand what they
do is to play with the words (use WHERE a lot).  Hopefully, it should be
obvious what is going on.

	I believe it is working properly, but if you find something wrong,
please let me know.

	I know I will be sorry, but "let me know if you have suggestions for

	PS:  RESTART will blow this away, as expected; you will have nowhere
to return to.

Message 1 of 1

Jul 11, 1983