Richard J. Nelson may not have been HP's first ... - Hewlett Packard

Richard J. Nelson may not have been HP’s first calculator customer (his first HP was an HP-35A
backordered in May and received on July 31, 1972), but he is certainly one of the most loyal and active in
terms of machines bought, used, analyzed, and written about. Here is his list of calculators in approximate
series order. Richard is not really a collector and many of HP’s customers own every one of HP’s
95 models.
HP-35A
HP-45A
HP-65A
HP-55A
HP-67A
HP-80A
HP-70A
HP-21A
HP-22A
HP-25A
HP-25C
HP-27A
HP-29C
HP-97A
HP-19C
HP-75C
HP-71B
HP-75D
HP-31E
HP-33C
HP-34C
HP-41C
HP-41CV
HP-41CX
HP-10C
HP-11C
HP-12C
HP-12Cp
HP12CP
HP-15C
HP-16C
HP-18C
HP-28C
HP-28S
HP-27S
HP-22S
HP-32S
HP-42S
HP-20S
HP-21S
HP-22S
HP-27S
HP-32SII
HP-17B
HP-17BII
HP17bII+
HP-10B
HP-38G
HP48S
HP48SX
HP48G
HP48GX
HP49g
HP48g+
HP48gII
HP50g
HP33s
HP35s
HP9g
HP9s
HP10s
HP20b
HP QuickCalc 10
Richard retired nearly three years ago moving from the California LA/Orange county area to Mesa
Arizona. With a 44 year career of electrical engineering, teaching electronics and technical writing
Richard has always used HP calculators, especially the high end programmables, in his work.
The HP65A inspired him to start a world wide HP calculator club in June 1974. He has edited, written,
and published well over 5,000 pages in monthly magazines dedicated to HP calculators for 12 years. Mr.
Nelson has paneled calculator sessions at several Engineering and Computer Conferences, and he started
the annual Hewlett-Packard Hand Conferences with the first one in September 1979. The next HP
Handheld Conference, HHC 2009, will be held October 3 rd & 4 th at HP in Fort Collins Colorado.
In addition to his HP calculator writing Richard also has a hobby of designing and building HP calculator
accessories. This year celebrates the 30 th anniversary of the HP-41/HP-IL calculator system which was
one of HP’s most popular machines and the first model with the expandability of four ports and an
alphanumeric display. HP-41 accessory examples are described.
As a leading writer in the calculator user community Mr. Nelson was often asked to give technology
reports to the US Navy. In one classified meeting he demonstrated how the HP-41 could be used to
control just about anything. He wired a tiny magnetic reed switch across the contacts of the HP-41 “E”
key. When the calculator was placed on a calculator stand input and output (external wireless) was
accomplished.
The HP-41 has an audible “beep” produced by a bender which was also capacitively coupled to a plate on
the stand. The “E” key could be “pressed” by an electromagnet in the stand and the audio tones could
provide control based on a running HP-41 program. Using a whistle switch (similar to the well known
sound activated The Clapper) Richard could walk around the room controlling the room lights and a
slide projector to show what was the latest in HP-41 applications. All of this was controlled by the HP-41
itself. This kind of thing is trivial and routine today, but having an affordable shirt pocket calculator do
this 29 years ago was “leading edge.”

Mr. Nelson was an avid promoter of program
barcode as a means of program publishing.
Another example of an “accessory” he built
was an HP-41 modem of sorts that utilized
the HP-41 wand code to send programs over
the phone lines. See the photo at the right.
The transmitter label reads, “This HP-41
accessory uses the HP HEDS-3000 wand to
convert barcode to an audio two tone signal
– 1200 & 2200 Hertz. HP-41 programs and
data may be recorded on an audio recorder or
transmitted by telephone using this concept.”
The receiver label reads, “TONES TO BAR
CODE SIGNALS, This HP-41C accessory
receives two tone (1200 & 2200 HZ) audio
signals from a telephone line or tape recorder
and converts them into a flashing light
emitting diode signal to be ‘read’ by an HP-
41C wand (model 82153A). A one hour tape
could store 36,000 bytes using a moderate
effective scan rate of 10 bytes per second.
Allowing ten seconds for voice announce-
Fig. 1 – The transmitter is on the top, the receiver on the bottom.
ments per program, the ten programs in the HP-41C Wand Manual would take 6 minutes, 36 seconds of
tape.” The first test was sending a program from California to another user on the East coast. No
modification of the HP-41 was required.
Mr. Nelson has authored hundreds of articles on HP calculators during the last 35 years. He taught an HP
48 programming class for several years and he managed the largest calculator software/documentation
project ever undertaken by the HP User Community. Known as the PPC ROM project hundreds of HP
users worked on writing 153 highly efficient routines that were programmed into a custom 8K ROM that
was then manufactured by HP. Over 5,200 of these ROMs were made. The 500 page PPC ROM User’s
Manual was written to illustrate what the users themselves thought was vital information for any software,
but especially for a programmable calculator.
The project took two years and at least one man century of effort. That is 876,581 hours of work by
hundreds of HP users around the world. All work was volunteered and if this project was professionally
done at a conservative 1980 $15 per hour, that would be $26,297 for each page of the document. In
today’s dollars (’80-‘09 cpi factor 2.587379) that would be an investment of $68,040 per document page.
All of this was done without email or the Internet. The PPC ROM User’s Manual is highly valued to this
day as a reference because of its completeness and it (and the ROM) recently sold for $150 on eBay. It
contained the listings of all ROM routines and applications programs in addition to them being provided
in barcode form using a unique high density printing format. The PPC ROM project was recently cited as
a prime example of organized community developed software at:
http://www.embeddedcomponents.com/blogs/2007/04/community-software-development-for-embedded-devices/#comment-421#comment-421
Keeping up with the latest technology and consumer electronics requires information gathering from
many sources. One of these is the annual Consumer Electronics Show in Las Vegas. Mr. Nelson has

attended more than 40 consecutive CES shows and has visited and written about every HP CES booth in
the process.
Mr. Nelson is still very active consulting, studying, and writing about HP calculators. He has what is
believed to be the largest library of HP Calculator documentation including letters, photographs,
brochures, owner’s manuals, service manuals, programs, solution books, newsletters (HP external and
internal), magazines, books, patents, magnetic media, operating system dumps, external reference
specifications, barcode manuals, and advertisements.
Many of his detailed articles on the latest HP calculators and calculator activities may be found on the
Internet at the HHC websites (http://holyjoe.net/hhc/) and several other sites including HP’s website
http://h20331.www2.hp.com/Hpsub/cache/392617-0-0-225-121.html.
Richard enjoys corresponding with other HP enthusiasts and may be reached at rjnelsoncf@cox.net.