HP Forums

Full Version: HP 41 / HP-IL Mini Plotter
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

I worked at HP Colorado Springs 1976-82. A year or two after the HP41C was introduced and I acquired one through inter-office transfer and was hooked enough to buy my own along with a card reader. An event occured in ~1979 which I remember vividly but have never been able to verify. Here goes:

A group of PHP engineers from HQ at Palo Alto visited our site with their newest widget: A shirt pocket plotter. The device was about the same size as the HP41 but shaped like a rounder-off box. It split in the middle and had telescoping rails. It opened to about 9 or 10 inches with half of the box on each end of the rail. One of the engineers plugged an HP-IL cable into the plotter and connected it to an HP41. He placed an 8.5" x 11" sheet of paper into it and commenced hitting keys on the calculator. The paper was transported through the plotter several times (to "register" it to the grit wheel, I was told). It then proceeded to plot the famous wire-frame image of the space shuttle.

Not long after I witnessed this the first of HP's grit-wheel plotters was introduced. I think it was a 7xxx series. I was told that the grit wheel/rubber wheel combo took years to develope since it was difficult to get the grit to stand up with the pointed end away from the wheel.

Has anyone on this forum EVER heard of this shirp-pocket plotter? I can just envision the prototype laying in some engineer's basement. What a find this would be, huh?

A few years ago I had my HP41C - the first one I bought - stolen. Even though I missed it, in the interest of being up-to-date, I purchased an HP48. It only took me a few days to realize that I could not live without my 41 so I sold the 48 and bought an HP41C, and a CV and a CX. I will never be without a 41 and when they pry it from my dead hands I hope my daughter knows how valuable it is.


I never saw the one you saw but there was a little crawling plotter/digitizer that was sold through surveyors co-op, as in the co-op rom). It was controlled by the 41 but i forget if it was il or some other hookup. I only saw one and it was cool. Anybody ever use one?

One such "crawling" plotter was presented by Jeremy Smith at one of the 1980's PPC conferences, and it was called the "Penman", which walked around the page and drew as it went. I believe the HP portable plotter mentioned before was the "Sweetlips" project, which ultimately became the 7470 plotter. I think it is described in fair detail in an HP Journal article back in 1981 or so.

Jake Schwartz