I was bored and found a HP-27S

[Steve Sabin]

(06-10-2014 03:52 PM)Katie Wasserman Wrote:  

(06-10-2014 11:18 AM)Don Shepherd Wrote:  In my opinion, one of HP's greatest achievements was the inclusion of programming constructs such as IF, sigma (loop), and L() and G() in the solver found in several calculator models, including the 27s. This made the solver more than just an equation solver; it is a real minimum programming language.

HP should have received some type of award for this solver, but we are all beneficiaries.

If I recall correctly the HP "step-by-step" publication called HP-27S/19B Technical Applications introduced L(), G() and other solver techniques. This was available when the 27S and 19B were first released. It showed how you could use the solver to compute coordinated transforms, solve linear equations, do complex variable arithmetic, find GCD and factor prime among other things. Pretty amazing for a "non-programmable" calculator.

I attended Oregon State University in the mid-1980s when getting my BSEE degree and worked as a student contractor briefly at HP Corvallis during that time writing application manuals during the summer of 1987. As payment, I requested an HP-27S, HP-28S, and an infrared printer (HP-82240A). I still have all 3 devices along with original boxes and manuals. The manuals I wrote are Science Student Applications for the HP-22S and Technical Applications for the 27S and 19B. I have copies of both.

To Katie’s point, I believe the Technical Applications booklet is where the LET and GET functions were introduced. I am a bit embarrassed looking back over these now because the applications book in particular reflects the naivety of someone who had not yet worked in the real world.

HP lent me a sewing machine-sized portable computer to write the manual. It was similar to the old COMPAQ portable computers of the day, before bona-fide laptops arrived, and had a lid-mounted keyboard that removed to expose a display with a reddish-orange tint rather than green. Ran HPUX as I recall and had a 3.5" floppy drive. The program to write the manual was not WYSIWYG and to fully check my work I had to drive about 5 miles from my residence to the Corvallis facility and connect to a printer to generate a hardcopy. It was sort of like HTML (or "reveal codes" in WORD) in that you had to remember to match the bold/un-bold, ital/un-ital, and other "on/off" pairs to bracket the affected text -- otherwise page after page of bold or some other text modifier would persist. There were also special commands to print things that looked like keys with boxes around them, menus with special lines before/after, and fonts that looked like the display characters. I don't recall if this was a standard app or something that HP wrote specifically for authoring technical documentation. I believe it was the latter.

I also had a 41-CV during that time and it remains my favorite. I wish I still had it. Loved RPN once you got used to it. I remember writing a gigantic program that would solve partial fractions. Saved me about 30 minutes one day taking a mid-term exam. I was the first one to leave the room because everyone else was slaving away. But in retrospect, 8 hours to the enter the coding and check it versus the 30 minutes it saved me in one test may not have been a great trade-off. But I certainly got to know the programming environment.