New user setting up HP 41CX

[Garth Wilson]

I penciled my key assignments on a key overlay. Sometimes you can find overlays on eBay, but since I'm the original owner of my 41cx, I got the beige-colored one with the 41cx brand new in 1986. Some assignments are easy to remember though, like CF (clear flag) being for °C to °F, and the shifted + and - keys being for HMS+ and HMS-. Unfortunately the 41 doesn't let you save USER key files like the 71 does, but you can have programs to re-assign keys. Maybe one of the modern modules has something to keep USER key files. I have not looked.

Since you're in EE though, you'll want the 41z module ROM image. Get that one and other favorites loaded into the NoV-64 module being made today. The 41z gives a true 4-level complex-number stack and tons of complex-arithmetic functions and enhancements, all written in assembly, vastly outperforming many of the functions in the Advantage module.

You might also want the Sandmath module ROM image loaded in, which gives gobs of math extensions. These are modules that have come out in just the last few years; IOW, new stuff is still coming out for the HP-41, although not from HP.

The port covers are frequently found on eBay too, but I don't think you'll save much power by unplugging things. The non-memory modules don't seem to take any power when the unit is off, and I used to get two years on a set of alkaline batteries (even with daily use) until I got a double extended memory module which seems to have taken it down to six months. I think the NoV-64 module will replace the extended memories anyway and give you even more memory. I have not looked at the power consumption.

In the 1980's I regularly used my 41cx to take data from a lot of lab instrumentation, using the HP82169A HPIL-to-HPIB interface converter which was more or less transparent, making HPIB (IEEE-488) equipment appear to be on HPIL. I also have the HPIL-to-RS232 and HPIL-to-parallel converters, and of course you can use all of these at once, in addition to the more-mundane disc or tape drives, printers, etc.. This kind of interfaceability was not carried through to any of the other calculators (not calling the HP-71 a calculator). I seldom take advantage of that interfaceability these days, but it's still important to me to have the capability.

The museum DVD has a ton of great material. You'll probably want to find what modules you want to load into the NoV-64, and get that. Before you know it you'll be into synthetic and assembly-language programming on it!