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Comments for Chasing Men Who Stare at Arrays http://lathwellproductions.ca/wordpress Catherine Lathwell's APL/A/J/K/Q Film Diaries Thu, 29 Aug 2013 01:58:52 +0000 hourly 1 https://wordpress.org/?v=4.7.9 Comment on It’s APL’s Birthday! Or is it? by They Saved the First CLEANSPACE back in 1966 - Silver Maple http://lathwellproductions.ca/wordpress/2011/11/27/its-apls-birthday-or-is-it/comment-page-1/#comment-45779 Thu, 29 Aug 2013 01:58:52 +0000 http://lathwellproductions.ca/wordpress/?p=5429#comment-45779 […] It’s APL’s Birthday! Or is it? by Catherine Lathwell […]

Comment on Against the odds, APL’s logarithm wins by Vance http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-39365 Tue, 25 Jun 2013 03:53:41 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-39365 I remember back in the mid 1970s, my Dad who worked for IBM in San Jose came home with a zipper bag designed to hold documents about APL which he was working on at the time. The bag said “APL A Programing Language” and there was a logo graphic of an apple, almost identical to the one Apple Computer later used. I am pretty sure it was before Apple Computer began using their apple logo. I think it had horizontal rainbow stripes, but no bite. When I later saw Apple Computer’s logo I thought they were related or that they had taken the idea for their logo from the APL logo used on that bag. Food for thought.

Comment on My hero! Shustek, APL/360 & 10 Years Later by Greg Bryant http://lathwellproductions.ca/wordpress/2012/10/10/my-hero-shustek-apl360-10-years-later/comment-page-1/#comment-29508 Mon, 06 May 2013 20:43:00 +0000 http://lathwellproductions.ca/wordpress/?p=5960#comment-29508 Excellent! Up and running in no time on Windows 7. Such a blast from the past. Brings back all of those memories in the computer lab of being clued to the selectric terminal.

Thank you so very much.


Comment on My hero! Shustek, APL/360 & 10 Years Later by Juergen http://lathwellproductions.ca/wordpress/2012/10/10/my-hero-shustek-apl360-10-years-later/comment-page-1/#comment-26687 Sat, 20 Apr 2013 09:53:24 +0000 http://lathwellproductions.ca/wordpress/?p=5960#comment-26687 Studying the source and the programming techniques used back in the ’60s is one side of the medal only, admittedly a very exciting one.

On the other hand there presumably are quite some people around having used APL\360 back in the days, who might be interested in seeing that historic gem back alive, signing on and having the old times revive.

The “MVT for APL” system, downloadable from


allows just that: In a few easy steps it can be installed on a Windows or Linux system to automatically build APL\360 from source and bring it up. Just follow the step by step instructions in the “Installation and Use of APL\360” section of the User’s Manual to bring up your very own APL\360 system.

Comment on Against the odds, APL’s logarithm wins by Andrew W. Fornallaz http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-19084 Wed, 20 Feb 2013 22:36:26 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-19084 Good choice.

Comment on Against the odds, APL’s logarithm wins by Roger Hui http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-18426 Thu, 14 Feb 2013 01:14:07 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-18426 Jon, I found an earlier reference for the comment on the comment symbol in the APL\360 User’s Manual, 1968-08, page 3.45:

Comments: The lamp symbol ⍝, formed by overstriking ∩ and ∘, signifies that what follows it is a comment, for illumination only and not to be executed; it may occur only as the first character in a statement, but may be used in defined functions.

The manual has at least one other “brush with humor”, depending on your sense of humor. Figure 1.2 depicts an APL\360 keyboard (which has a 5-pointed rather than 6-pointed star, by the way), accompanied with the following paragraph:

The special characters, most of which are produced with the keyboard shifted, generally have some mnemonic connection with their alphabetic or numeric correspondents. This may be appearance (⍵ over W), Greek-Roman equivalence (⍴ over R), sequence ( ≠ over 3 4 5 6 7 8), or some — possibly far fetched — relationship between the APL function represented by the symbol and the letter (* over P for power, ‘ over K for “kwote”, and ⌈ over S for ceiling).

Seems pretty hilarious to me.

Comment on Against the odds, APL’s logarithm wins by McGrew http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-18384 Wed, 13 Feb 2013 05:30:31 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-18384 Discussion of the lamp symbol reminds me of a point from the early APL Language Manual from IBM (GC26-3847, circa mid-1970s). This was of course a serious formal manual, but I believe that it was Adin Falkoff who provided its one and only brush with humor: Under the COMMENTS heading, the manual explains that “The lamp symbol (the cap-null) signifies that what follows it is a comment, for illumination only and not to be executed…”. I have always liked the idea that the lamp is for illumination. Of course.

I also want to extend thanks to Roger for clarifying the discussion about zero and empty vectors. The quote was indeed from Donald McIntyre. I thought that Donald’s comment was brilliant, and I would certainly never claim any credit for that.

Comment on Against the odds, APL’s logarithm wins by aprogramminglanguage http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-18341 Tue, 12 Feb 2013 16:21:09 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-18341 Dear John, THAT is so cool.

Heh… Roger, you paper http://www.jsoftware.com/papers/log.htm is generating more buz an excitement than my logo. Nice job!

Comment on Against the odds, APL’s logarithm wins by John Baker http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-18334 Tue, 12 Feb 2013 14:54:22 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-18334 A great choice Catherine. Just yesterday I was staring at this very symbol in some old APL logarithmic regression code that I am converting to C#. The beauty of circle star is nowhere to be seen in C#, but, with the increasing use of Unicode, elegant symbols are making their way into many languages. In another generation APL will not be seen as strange.

Comment on Against the odds, APL’s logarithm wins by Roger Hui http://lathwellproductions.ca/wordpress/2013/02/11/against-the-odds-apls-logarithm-wins/comment-page-1/#comment-18319 Tue, 12 Feb 2013 04:03:24 +0000 http://lathwellproductions.ca/wordpress/?p=6130#comment-18319 > And besides, to quote a story told by Jon McGrew –
> “We have the Arabs to thank for zero.”

The story is better than your quote indicates. From http://www.jsoftware.com/papers/APLQA.htm#nothing:

• [Commenting on the empty vector:] I think we have the Arabs to thank for inventing zero, but I know that we have Dr. Iverson to thank for inventing nothing.

— Donald McIntyre, APL Users Meeting, 1980-10