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FIGURE 4. Tavernier – Gravet with the Reverse E Chisel Cursor

Now, I need to find a pattern for a K & E duplex chisel cursor, for all of us who have the early 1891 Cox patent rules, but again with no duplex chisel cursors.

Look at the pictures and tell me which is real, and which is faux?

FIGURE 5. Comparing the Tavernier - Gravet Old and New Cursors (Which Is the Old One?)

In Memoriam

IJzebrand Schuitema

IJzebrand Schuitema, noted slide rule historian, premier collector, His legacy will be preserved by his four books, 19 articles in founder and member of the Dutch Kring, died 22 August 2013 at the the Journal of the Oughtred Society, and articles in other age of 84. He donated his vast collection to the Arithmeum in Bonn, publications. His many friends will remember his inspiring, Germany in 2008 (see article on page 56). energetic, and creative character, and remember his shining example as a driven collector.

Hewlett Packard Commemorative Calculators

Otto van Poelje

Today’s electronic pocket calculators have become so This special 15C can be recognized by the label “Limited widespread and cheap (or even free) that they are hardly Edition”, see Figure 1. Some disappointment was expressed interesting anymore as “collectable” calculating instruments. in HP discussion forums about the production quality (in the However, an exception is for the calculators from Hewlett Far East) of this model; the typical HP “touch & click” feeling Packard, which already have been collected for many years of the original keys appears to have diminished. by a large group of enthusiastic HP fans. After all, Hewlett Packard was the firm that in 1972 brought to market the very In 1982, this calculator was the (scientific) top model in the first scientific pocket calculator, the HP35, also called the “landscape format” series 10C, 11C, 12C, etc. Some special “Slide Rule Killer” or the “Mother of All Scientific functions, new at that time, were added, such as extension of Calculators”. The prime reference for collectors of HP the RPN stack to complex numbers, matrix calculations (up calculators is www.hpmuseum.org by David Hicks. to 8x8), statistics, formula solver, and numerical integration. Programming of key sequences had already been provided To again draw attention to their accomplishments in this field, in HP calculators since the HP65 in 1974. HP announced in 2012 a re-issue of the famous 15C scientific calculator in a limited edition to celebrate the 30th One of the selling points was the admission of these anniversary of this 1982 top model. The functions of the new calculators for use by students during exams, especially in an 15C have remained the same (RPN, transcendental functions, era of emerging alphanumeric calculators and PDA’s. solver, statistics, matrices, etc.), but the speed has been The absence of text was actually considered an advantage, in increased a hundred-fold by using a new processor (ARM). order to prevent using the calculator for cribbing and cheating! 28 Journal of the Oughtred Society

FIGURE 1. HP 15C Limited Edition

The 12C became a big commercial hit, even competing with its own successors, such as the HP10B or the HP14B. Possibly the rich colour scheme (the 12C Gold) was helpful, or the fact that the model was one of the few allowed for use during CFA exams in the USA.

The success of the 12C is also visible in the large number of computer animations that have been made available for PC’s, PDA’s, iPhones, iPads, Android, etc. During the long commercial life of the 12C (new 12C’s are still being sold in 2013!) internal improvements have been introduced quietly to FIGURE 2. HP Logo 50 increase performance. This new 15C is not the first “special edition” of an HP calculator. By 1989, two 50th Anniversary models were offered of the HP14B (Business) and of the HP32S (Scientific), characterized by the logo shown in Figure 2, next to the HP logo. This anniversary refers to the year 1939, when the founders Bill Hewlett and Dave Packard tossed a coin to determine the order of their names in the new firm’s trade mark.

Another famous model is the HP12C from 1981, a business model. The “C” signified “Continuous Memory”, i.e., memory contents were preserved when the power was off. This model proved that the RPN (Reverse Polish Notation) key input method could also be learned by others than engineers. A great many financial specialists have used (and perhaps still do use) this calculator for interest calculations, cash flow analyses, annuities, bond performance, etc. FIGURE 3. HP 12C 30th Anniversary Edition

To celebrate the success of the 12C, a 30th Anniversary Edition (see Figure 3) was released in 2011, keeping all the original functions, but again with the speed increased. Remarkably the 12C pictures in sales material show the value of π = Volume 23, Number 1, Spring, 2014 29

3.141592654 on the display although this model has neither trig functions nor a key button for π.

Some aficionados like the common 12C Gold better for the luscious gold ribbon around display and keyboard. Even before the 30th Anniversary Edition, the Model 12C had become so popular that an extended Platinum version (see Figure 4) was released in 2003, six times faster and with four times more memory.

Another interesting addition was the algebraic key input method, next to RPN. Apparently not all financial profes- sionals were able to learn the unusual sequence of operations in RPN.

The Platinum keyboard included some additional functions to , e.g., allow algebraic entries RPN and ALG above the keys CHS FIGURE 4. HP 12C Platinum and EEX, to choose the input method. In a later version of the Platinum, key functions were added for brackets in compound algebraic operations (for some reason forgotten in the very first Platinum models!).

In addition, a square function was added, as well as a “recover” key to undo unintended Clear operations. Trig functions are still missing in the 12C Platinum.

The Platinum version was released as a 12C anniversary version in 2006. The 12C Platinum 25th Anniversary Edition should not be confused with the later 30th Anniversary Edition of the common 12C.

Whether we can still expect real innovations in HP pocket calculators is doubtful. The current trend is directed more towards Smartphones and tablets, the jack-of-all-trades devices that can have an “app” installed for any type of calculation. See Figure 6 for an example of an HP12C “app” for the Apple iPhone.

One other model of HP calculator should be mentioned, also having a clear commemorative intention although there is no FIGURE 5. HP 35 of 1972 (left) vs. HP 35s of 2007 (right) inscription to that effect. To honor the very first model HP35 from 1972, Hewlett Packard brought to market in 2007 (35 years later) the model HP35s, a scientific calculator in which the original 14 mathematical functions of the original HP35 were increased to an astonishing extent.

To summarize: the HP35s can do all that the HP35 and its successors could do, the only exceptions being the most advanced financial functions and the RPL language that was used in the graphic calculator HP48. In spite of the enormous differences in functionality, the HP35s is, by its retro-styling, a visible homage to the HP35 of 1972, see Figure 5.

FIGURE 6. HP 12C “app” on an iPhone