User talk:RTC

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[edit] Image copyright problem with Image:Lake Havasu City London Bridge.jpg

Thanks for uploading Image:Lake Havasu City London Bridge.jpg. However, the image may soon be deleted unless we can determine the copyright holder and copyright status. The Wikimedia Foundation is very careful about the images included in Wikipedia because of copyright law (see Wikipedia's Copyright policy).

The copyright holder is usually the creator, the creator's employer, or the last person who was transferred ownership rights. Copyright information on images is signified using copyright templates. The three basic license types on Wikipedia are open content, public domain, and fair use. Find the appropriate template in Wikipedia:Image copyright tags and place it on the image page like this: {{TemplateName}}.

Please signify the copyright information on any other images you have uploaded or will upload. Remember that images without this important information can be deleted by an administrator. If you have any questions, feel free to contact me. Thank you. Ricky81682 (talk) 07:23, 2 February 2006 (UTC)

[edit] Vanadium

The article says that vanadium is a grey-white metal. Is there something different about the vanadium in the picture you took? Like is it oxidized or something (you can probably tell I don't know much about chemistry)? Anyway, that picture is of a yellow brown metal unlike these: http://images.google.com/images?q=vanadium&hl=en

Please answer soon, I am doing a project on Vanadium. †Sƒ 20:27, 3 February 2006 (UTC)

Wow! I can't believe I was right that it was oxidized :). I guessed that because of the brownish tin that iron gets when it rusts...

Anyway, being sleep deprived and in a rush (which is not usual for me), I forgot that I was researching Yttrium (I basically initially thought I was researching vanadium, and then I found out it was Yttrium). Thanks or the help anyway though :)

On the ~s, I don't know why I forgot to that...

Do you think a different picture of Vanadium should be used? Like a 'non-oxidized', solid block?

LOOK :) †Sƒ 20:33, 3 February 2006 (UTC)

[edit] ENIAC

Hi there, I've been doing some work to make the first § of this article clearer. Could I ask you to look over my suggested changes at Talk:ENIAC, to make sure I'm not introducing errors? Very much appreciated, JackyR 21:20, 12 February 2006 (UTC)

[edit] Please check your WP:NA entry

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Thank you, and have a wiki wiki day! BD2412 T 03:07, 17 February 2006 (UTC)

[edit] FORTRAN article and 3-way branch on 704 ?

Hi RTC. I had put something a while ago in the FORTRAN article about the Arithmetic IF statement and the three-way branch on the early implementation being close to a machine instruction. You removed it saying there was no 3-way branch on the 704. I will double check what was going on then. I remember first-hand CAR/CDR in LISP. Thanks and Bests. --- (Bob) Wikiklrsc 23:30, 12 September 2006 (UTC) (talk)

Hello RTC. Thanks for your kind reply and thoughts. I started out on the IBM 1620, working on the FORTRAN compiler and later transition tools to convert to IBM 1130 FORTRAN. I will do some checking, as well. I was told the bit about the "three-way-branch" and the Arithmetic IF statement by some of the original IBM people who worked on the original FORTRAN ... or I got it mixed up somehow in the cobwebs of my memory ! Bests. --- (Bob) Wikiklrsc 13:10, 13 September 2006 (UTC) (talk)

I found a few backing references on the web. One in an ACM article.

"Debunking the myths about Fortran", ACM SIGPLAN Fortran Forum archive, Vollume 18, Issue 2(August 1999) table of contents, Pages: 12 - 21, Year of Publication: 1999, ISSN:1061-7264, Author: Craig T. Dedo, Elmbrook Computer Services, 17130 W. Burleigh Place, Brookfield, WI, Publisher ACM Press, New York, NY, USA

In this, the author says:

"The arithmetic IF mapped to a peculiar three-way branch. instruction that was part of the instruction set of the IBM 704, the computer for which Fortran was ..."

Since I don't have the article in hand, I am not sure what it says precisely !

And in the text, Programming Languages by Bruce J. Maclennan, there is reported to be a reference to FORTRAN's arithmetic IF and a 704 instruction. "Principles of Programming Languages: Design, Evaluation and Implementation", New York: Holt, Rinehart and Winston (now, Oxford University Press), 1983. Second edition, 1987. Third edition, 1999. [1]

"In FORTRAN, control structures were based on an IBM 704 branch instruction. The arithmetic IF-statement in FORTRAN II IF(e)n1,n2,n3 it means If e<0 goto n1, e=0 goto n2, e>0 goto n3 ..."

Of course, there's a copy of the 1955 IBM 704 manual !

Bests. --- (Bob) Wikiklrsc 20:03, 13 September 2006 (UTC) (talk)

Hmm. But no 3-way branch instruction actually used for the arithmetic IF ? Saw your updates to the article itself. Looks good. Maybe we'll have to write to John Backus. Thanks. --- (Bob) Wikiklrsc 20:36, 13 September 2006 (UTC)

Hi RTC. Okay, I see what you've done with the information from the manual. Comparing storage to the Accumulator on the 704, of course, is more expensive than register to register ! But they could have cutely used the CAS instruction even if it was less efficient ! ;) I will try to write to someone. Bests and Thanks. --- (Bob) Wikiklrsc 17:46, 14 September 2006 (UTC) (talk)

RTC, thanks for the code sequence you think was generated for the Arithmetic IF in FORTRAN on the IBM 704. I think canonically it is three instructions using simple branches. However, classical code generators would use only two branches and fall through to the third case.
TZE n2
TMI n1
[fall through here to default code for > 0 case]
So only two instructions are needed for the branches traditionally.
I will look into the actual code generated from the IF statement for the first FORTRAN compiler for the IBM 704 if I can get in touch with old IBM colleagues from that era.
Now as far as the FREQUENCY statement in FORTRAN, it was used originally and optionally to give branch probabilities for the three branch cases to bias the way code was generated and order of the basic blocks of code generated, in the global optimisation sense, were arranged in memory for optimality. The first FORTRAN compiler used this weighting to do a Monte Carlo simulation of the run-time generated code at compile time. Very sophisticated. It's in the original article in 1957 on the first FORTRAN compiler implementation by J. Backus, et al. [2] ... later on the FREQUENCY statement had no effect on the code, and was treated as a comment statement, since the compilers no longer did this kind of compile-time simulation. Oh, yes, you might be interested in part of my webpage on compiling [3] ... Bests. --- (Bob) Wikiklrsc 13:28, 16 September 2006 (UTC) (talk)

Here is part of the 1957 paper, "The FORTRAN Automatic Coding System" by Backus, et al., this snippet on the FREQUENCY statment and its use in a compile-time Monte Carlo simulation of the run-time to optimise the code generated. Quoting ...

The fundamental unit of program is the basic block; a basic block is a stretch of program which has a single entry point and a single exit point. The purpose of section 4 is to prepare for section 5 a table of predecessors (PRED table) which enumerates the basic blocks and lists for every basic block each of the basic blocks which can be its immediate predecessor in flow, together with the absolute frequency of each such basic block link. This table is obtained by an actual "execution" of the program in Monte-Carlo fashion, in which the outcome of conditional transfers arising out of IF-type statements and computed GO TO'S is determined by a random number generator suitably weighted according to whatever FREQUENCY statements have been provided.

Bests. --- (Bob) Wikiklrsc 14:31, 16 September 2006 (UTC) (talk)

Kind of interesting. The IBM CE Manual for FORTRAN I, II, and 709, from 1959. --- (Bob) Wikiklrsc 00:50, 20 September 2006 (UTC) (talk)

[edit] 1401, Fortran 3 way

I added about 4 new topics in the 1401 discussion, would appreciate your looking at them. I'll act on your recommendations, believing that the two of us are "good enough".

btw, as to the Fortran 3 way branch... I had added a lot of references to the Fortran article (my idea of encyclopedic) as well as other things such as the 2nd implementation of Fortran, but then deleted it all after someone reorganized it to uselessness (well, a newby, I was only learning how widipedia works). If you go to the 22:04 25 August 2006 (last) version, then to Fortran II, there is a link to the "System Manual for 704 and 709 Fortran", 1960. In that manual the IF statement expansion is given -- using TZE,etc. No need to contact Backus. (there is, of course, the small possibility that the implementation changed between 1957 and 1960; If the 709 dropped the CAS instruction ....). 69.106.254.246 16:07, 18 September 2006 (UTC)

Good news, I suppose, is that when I stopped looking at Fortran I then ventured over to the 650 and 1401. Or maybe that's bad new for those articles!

I checked the 7094 manual; it lists the CAS instruction. It was not dropped. -- RTC 22:12, 19 September 2006 (UTC)

[edit] Seeing as how you live in Sunnyvale and are working on the CHM restoration project ...

... you might want, or know someone who would want, an ancient (1950s?) Tektronix scope that has been sitting in my Cupertino garage for years. A Lockheed discard, it is not pretty. Likely hasn't been powered on for over 30 years. Have the manuals & connectors for it. CHM already has several, Digibarn has one. Have been meaning to contact instructor's at local high schools, but haven't gotten around to it (haven't wanted it to go to someone who would cut it up for parts, except for servicing similar scopes - that would be ok). 69.106.254.246 05:57, 20 September 2006 (UTC)

Hi. If you've responded to the above, I missed it. 69.106.232.37 20:12, 27 September 2006 (UTC)

[edit] Hollerith 070 Sorter

It's a 1908 product, thus can't be an IBM product. The reference has "(IBM) Hollerith 070". If that's not acceptable, then wouldn't "Hollerith 070 - 1908 Vertical Sorter" be correct? Hmmmm, how do you plan to list Lotus products? 69.106.232.37 06:32, 5 October 2006 (UTC)

[edit] new memory cat

Seeing as all memory devices are destined to end up in the "former" group, is another cat really a good idea? It might be useful if the same devices were not in the more general memory cat, but if we do that separation the "former" group would end up being much larger than the current. I just don't see enough utility to make up for the potential confusion. Maury 13:14, 2 November 2006 (UTC)

Fair enough. Maybe we should merge them or something? Or maybe a link on the cat page itself from one ot the other? Maury 22:38, 2 November 2006 (UTC)

[edit] 601 date

The reference gives date as 1931. 1933 is given as date for a special model. Shouldn't there be a different reference if you think the 1931 date is wrong? 69.106.232.37 16:27, 14 November 2006 (UTC)

I looked at the reference for the 600 in 1931. It says that the 601 was introduced in 1933 as an improvement. -- RTC 20:11, 14 November 2006 (UTC)
That is correct. The 1933 601 is an improvement of the 1931 601. Look at the Columbia link again. I added details to IBM Products. The Brannon book (I used my copy) is available online at the Columbia History site -- I haven't looked up the url. This would be the first time, I think, that different models of a machine are listed in IBM Products. Not sure which way you want to go with this, but the details I added shouldn't be left there as they are not consistent the level of detail for other listings. Thanks, 69.106.232.37 20:50, 14 November 2006 (UTC)

[edit] Punched card

By the way, please look at the discussion for Punched card. Responding the the issues raised - that we can't call it Punched card unless it discuss all punched cards - my intent is to rename it "Hollerith, IBM, and UNIVAC punched cards". That satisfies one point of the issue raiser. 69.106.232.37 20:50, 14 November 2006 (UTC)

Name seems too long. How about "Punch card (data processing)" or "Punched card (data processing)"? Then have a disamb page for pointing to "Punch card (textile industry)", "Punch card (...). -- RTC 06:21, 15 November 2006 (UTC)
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