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Newsgroups: comp.sys.handhelds
Subject: RE: The First (?) HP Calculator (long)
Message-ID: <9975CBD8C0000812@gacvx2.gac.edu>
From: Harold Climer <HCLIMER%UTCVM.BITNET@CUNYVM.CUNY.EDU>
Date: Fri, 07 Jun 91 19:27:49 EDT
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In-reply-to: Your message of Fri, 7 Jun 1991 14:17 CST
To: handhelds@gac.edu
Lines: 91

On Fri, 7 Jun 1991 14:17 CST you said:
>Subject: The First (?) HP Calculator (long)
>Message-ID: <1991Jun6.153021.10025@ll.mit.edu>
>From: wjc@llex.ll.mit.edu ( Bill Chiarchiaro)
>Date: 6 Jun 91 15:30:21 GMT
>Sender: news@ll.mit.edu
>Organization: MIT Lincoln Laboratory
>Keywords: Not the HP-35
>Article-I.D.: ll.1991Jun6.153021.10025
>
>
>Seeing the recent discussions of HP calculator history, I've decided
>to add a couple of postings which might be of interest.
>
>So far as I know, the first HP calculator was the Model 9100A
>introduced in 1968 at a price of $4900 (this is from the HP Journal of
>May 1974 -- the one that described the HP-65).  It was a desktop
>machine, considerably larger than, say, an HP-97.
>
>The 9100A was quite an interesting machine, and it clearly showed the
>design philosophy evident in the later HP calculators.  It was
>programmable and had 16 registers.  Fourteen of those could hold
>either a real number or 14 program steps.  The remaining two registers
>could not be used for program storage.  Thus, the 9100A could hold a
>maximum of 196 program steps.  There was a built-in magnetic card
>reader/writer which used credit-card sized mag-cards.  The cards could
>be fed in either of two orientations and thus could contain two 196-step
>programs.  Provisions were made for convenient overlaying or chaining
>of programs.
>
>Until the HP-28/HP-19 series, this was the last machine to show more
>than one level of the stack at a time.  The 9100A had three stack
>registers called X, Y, and Z.  All three were simultaneously shown on
>the CRT (!) display.  Of course, the 9100A used RPN.  It could display
>in either fixed point or floating point.  The range of floating-point
>exponents was -99 to +99.  The available precision was 10 digits,
>internally it was 10.  The stack operated a little differently than we
>are used to.  Entries from the keyboard went into the X register, but
>results of dyadic operators were returned to Y.  This made repeated
>operations easier (X was left unchanged).
>
>The built-in functions included: the four basic functions, square root,
>log, ln, and e^x; sin, cos, tan, and their inverses; sinh, cosh, tanh,
>and their inverses; polar-to-rectangular conversion,
>rectangular-to-polar, and vector addition and subtraction; absolute
>value and extract integer part.  Trig functions could operate in
>either degrees or radians.  A PI key was also included.
>
>The implementation and realization of the 9100A architecture was quite
>fascinating.  The user memory was 368 words by 6 bits of magnetic
>core!  There were essentially two levels of microcoding with a 64 word
>by 29 bit "Control" ROM and a 512 word by 64 bit "Program" ROM.  The
>Control ROM was a wire braid toroidal core memory.  The Program ROM
>was a 16-layer PC board which used inductive coupling from its drive
>lines to the sense lines.  HP was proud that they had achieved a
>density of 1000 bits per square inch.
>
>The logic was discrete transistors, diodes, and resistors.  The memory
>addresses and some other state information were kept in 40 J-K
>flip-flops.  The internal operations were performed by hard-wired
>logic gates.  The total number of semiconductors was, I believe, only
>a few hundred.  The clock period was 825 ns.
>
>The 9100A had an output port for driving printers or other
>peripherals.
>
>I had the opportunity to use one of the machines a few years ago and
>it was actually quite nice.  The speed wasn't bad.  A trig function
>would take about 280 msec and an addition or subtraction would take 2
>msec.  A sample factorial program supplied by HP took less than half a
>second to compute 69!; a similar program on my HP48SX to just over
>half a second.
>
>Now for a question:  Does anyone know if HP made any other calculators
>between the 9100A and the HP-35?
>
>
>Bill Chiarchiaro
>wjc@ll.mit.edu

   I remember using one in the late 60's or early 70's for a course in
Statistical Meteorology at Texas A&M. Also there was on that looked similar to
the 9100A that could be programed in BASIC. Eric T. Lane(Physics Department)
said he thought it was the 9300 ? I used the "9300" at Toswson State University
in the late 70's.
                 By the way how did the lacross championship game come out last
Saturday. I had to do some yard work and only caught about 15 min of it on CBS.
Towson was losing 11 to 7.

                                       Harold Climer
                                       Physics Department
                                       U. Tennessee at Chattanooga