Newsgroups: comp.lang.apl
Path: watmath!watserv2.uwaterloo.ca!torn!cs.utexas.edu!uunet!utcsri!geac!itcyyz!yrloc!hui
From: hui@yrloc.ipsa.reuter.COM (Roger Hui)
Subject: Re: Two J Implementation Questions
Message-ID: <1992Oct21.231634.17756@yrloc.ipsa.reuter.COM>
Organization: Iverson Software Inc.
References: <Bw9nFy.E0s@NCoast.ORG>
Date: Wed, 21 Oct 92 23:16:34 GMT
Lines: 33

Peter Petto writes:
 
> 1) Will locatives be implemented soon?  I see their operation
>    clearly detailed in Appendix C of the dictionary, but
>    I don't find them working.  (Needless to say I think they
>    are a great idea and am eager to use them.)
 
They were first defined in "An Introduction to J" in January 1992 and
are not yet available.  In that time, other projects have received higher
priority (releasing the source, order-of-magnitude speed-ups, Windows).
Perhaps now is an appropriate time to look again at locatives.
 
> 2) Donald McIntyre mentioned using J on an HP95LX.  Can the
>    session manager be set for a 40x16 screen?  Has anyone compiled 
>    J to execute in place (XIP) as is possible on that hardware?
 
The HP 95LX scrolls a 25 by 80 logical screen within a 16 by 40 physical
screen, and informs enquiring programs that the screen size is 25 by 80.
This interferes with the scrolling offered by the J session manager,
and can be ameliorated by implementing a start-up parameter for J.
 
While running J as an XIP program may offer efficiencies over running it
as a standard DOS program on the HP 95LX, the current volume of J usage
on the HP 95LX does not justified additional expenditure of resources --
ROM building tools, software changes to use bank switching, etc.
If the same effort were spent on the base version many more users would
benefit thereby.  Anyway, with the pace of hardware improvements,
I expect that the HP 95LX will soon be 386 compatible with extended memory,
reducing greatly the importance of this method of enhancing RAM availability.

------------------------------------
Roger Hui, Iverson Software Inc., 33 Major Street, Toronto, Ontario  M5S 2K9
Phone: (416) 925 6096;  Fax: (416) 488 7559
