HP Forums

Full Version: 3421 Control Module for HP-41C
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

Can anyone tell me what a 3421 Control Module does on the HP-41C? I have never seen this one before. Currently on e-bay.

I don't have one of these, but AFAIK the module is intended for use with the HP-3421 Data Acquisition/Control Unit .



It contains programs fro controlling the HP-3421 data Acquisition unit. This unit is an old HP instrument that can be interfaced either HP-IL, HP-IB, or RS-232 and has cards that cna connect to the outside world (volts, frequency, etc.)

What is the item number on eBay for the item, I haven't found it? I'm asking because I know there is another ROM that was created by HP that shows up as either "CONTROL" or "MONITOR" with a CAT2 that was used for internal testing in particular with HP-IL devices. I believe it mimics most of the HP-IL Development ROM functions. More than likely the eBay listing is for the HP3421A Data Acquisition and Contorl ROM is it labeled.

I have used one of these ROMs and it says "3421 Control" on the ROM case. The HP 41C CAT 2 commands shows "--INST 1B--" The ROM contains many programs which control the 3421A via HP-IL. Some of the more useful programs is the Data Logger (DL) which allows the user to setup complex data logging applications that acquires data from multiple channels and output data on digital tape and/or thermal printer. The ROM also came with two HP-41C keyboard overlays - one for the DL program and another for a Front Panel (FP) program which allows you to measure (V, Ohms, Freq, Temperature.

I hope this information is useful. I think it is a useful ROM especially if you are a novice at interfacing with HP data acquisition systems. If you have any additional questions, feel free!

The eBay auction number is 3053369397 - a fullnut 41CV with Time Module and the 3421 Control module. I would suspect that the Time Module was acquired for providing inputs to the 3421.

I didn't know what the 3421 was either -- I thought it might be a rocket-launch game: "4-3-2-1 Mission Control"