41C data collection memory

[cruff]

Here is a 41C related thread to get things started.

When I started college, I had a TI59 and the printer. I was working in a chemistry lab at the Denver Research Institute for work study, and my boss had an HP45, then he acquired an HP41C, which was great fun to play. He encouraged me to also get an 41C, saying he knew someone who would pay top dollars for my TI59. So, with that arranged and the money in hand, we made the trek to downtown Denver to the Auraria campus book store where HP calcs and accessories were readily available. Needless to say I spent days reading the manuals and trying things out. It was a big step up from the TI59 in capabilities.

I eventually was able to scrape together the money for the quad memory and time modules. With that combo, I was able to use my 41C to collect data about the inter-arrival times of cars at a traffic light controlled intersection for use in a modelling project in my statistics class. I was able to demonstrate that at that time of day (late afternoon), if the westbound traffic doubled, there would be excessive delays unless the timing of the signal were changed.

[davetheguru]

The 41C -- I remember it well. I actually still have it, memory modules, time module, card reader, printer. I got them about 30 years ago when I was in college, in a EE program. I still have the hardware somewhere (I'd have to recall where I have packed them). Since getting a '48-GX, a '49g+ and '50g, the 41C stuff stayed in storage.

the 41 is a great calculator. I really liked the time module. I wish calculators, watches, etc would have incorporated it's accuracy factor technology to be more accurate (better than the 1 or 2 seconds a day most have). Indeed, I even wrote a control alarm program for my '48GX to emulate periodic correction to the time (but not as nice as the fine grain correction the time module would do).

I don't recall modules for data collection for the 41C. Either I didn't know about them or they were beyond my budget. I could have had lots of fun collecting data with the '41C with it.

The 41C did not have a serial port for talking to other instruments (that I have). Yet the '48 and '50 do. So interfacing the '50 to the real world is not hard.

[Garth Wilson]

(01-25-2014 06:34 PM)davetheguru Wrote:  the 41 is a great calculator. I really liked the time module. I wish calculators, watches, etc would have incorporated it's accuracy factor technology to be more accurate (better than the 1 or 2 seconds a day most have). Indeed, I even wrote a control alarm program for my '48GX to emulate periodic correction to the time (but not as nice as the fine grain correction the time module would do).

After I got my HP-71, I wrote programs for it to do some of the time stuff that was already included onboard on the 41cx. (The 41cx has the time module built in, so it does not take up a port space.) It was a bit of a disappointment that the 71 didn't have as much there, but nice of course that it could still be done with user-supplied programs.

Quote:I don't recall modules for data collection for the 41C. Either I didn't know about them or they were beyond my budget. I could have had lots of fun collecting data with the '41C with it.

HPIL allowed it to be connected to loads of instruments for data acquisition and control. I bought my HPIL module with the Extended I/O module already built into it. The Extended Functions/Extended Memory module (which is already built into the 41cx, along with the time module, text editor, and a couple of other things you couldn't get on a 41c or cv) helped too. Then I got a combined double Extended Memory module. Extended memory works in files. Many modules made certain jobs easier that were already possible without them though. For example the first piece of equipment I ever interfaced my 41 to (besides the printer and tape drive) was the HP3421A data-acquisition unit for which there was an HP-41 module but I just looked up the 3421A commands in the manual and never bought the module. Later I interfaced the 41 to relay matrices, DMMs, signal generators, etc..

Quote:The 41C did not have a serial port for talking to other instruments (that I have). Yet the '48 and '50 do. So interfacing the '50 to the real world is not hard.

For the 41 to interface to RS-232, you use the HP82164A or FSI164A HPIL-to-RS232 interface converter. The latter came with two serial ports standard, and optionally up to eight, and of course HPIL allows lots of devices to be connected at once, meaning you could have even more if you wanted. I interfaced my 41 to IEEE-488 with the HP82169A HPIL-to-HPIB interface converter, and to parallel with the HP82165A HPIL-to-parallel interface converter. I'd say the 41 was way ahead of the 50 in real-world interfaceability.

[Joe Horn]

(01-25-2014 11:05 PM)Garth Wilson Wrote:  After I got my HP-71, I wrote programs for it to do some of the time stuff that was already included onboard on the 41cx. (The 41cx has the time module built in, so it does not take up a port space.) It was a bit of a disappointment that the 71 didn't have as much there, but nice of course that it could still be done with user-supplied programs.

If you ever get a hankering to play with the '71 again, you can add all of the 41CX alarm functionality to the '71B by installing the ALARMLX lexfile by Mastny J. Michael. Here's an excerpt from its documentation (which I wrote, because he never wrote any documentation for it):

“ALARMLX gives to the HP-71 the same power that the HP-41CX enjoys: the ability to set multiple alarms for any time and date, message or control alarms, interrupting or non-interrupting, and one-shot or repeating alarms. One new feature which the HP-41CX does not have: you can specify how many times a repeating alarm is to activate before clearing itself. ALARMLX also contains equivalents of the HP-41CX's ALMCAT (alarm catalog), and CLRALMS (clear all alarms). New to ALARMLX, however, is the ability to clear just the one alarm at a given time and date.”

You can download ALARMLX and its documentation from here:
http://holyjoe.net/HP71/lexlist.htm
It's the very first lexfile on that page.

[Garth Wilson]

I did all that, but not in a LEX file. It seems like there was only one small limitation, and I can't remember what it was. I did have the multiple alarms of different types though, and with multiple repeats, mostly patterned off the 41's alarms, but took advantage of the 71's added capabilities to make the user interface a little more friendly. The non-alarm time functions like day of week and days between dates were in some other utilities I got from an HP applications book if I remember correctly. On both the 41 and the 71, I also did a Daytimer kind of thing where you can put in things you want it to remind you of. When you turn them on, they look for date matches in the DAYTIMR file and see if there's anything they're supposed to remind you of. If there's not, the next thing they look for is any pending alarms, and if there is at least one, they will tell how much longer before it's due. If there are no alarms either, the 41 or 71 just show the time and date. The 41 takes a couple of seconds to do all this as it's much slower than the 71. I think I gave Geir the 41 program when we met in L.A. last summer.

[Garth Wilson]

Thanks Joe for the link! I was unable to get to it earlier as our ISP has been having problems for the last few days. I have a lot of those LEX files from the CHHU Chronicle, but there are ones I did not have. I tend to forget which ones I had because at one point I used another utility to merge a bunch of LEX files into one, to make it faster to re-load everything when I was new to Forth and crashed it once in a while.

[davetheguru]

(01-25-2014 11:05 PM)Garth Wilson Wrote:  After I got my HP-71, I wrote programs for it to do some of the time stuff that was already included onboard on the 41cx. (The 41cx has the time module built in, so it does not take up a port space.) It was a bit of a disappointment that the 71 didn't have as much there, but nice of course that it could still be done with user-supplied programs.
HPIL allowed it to be connected to loads of instruments for data acquisition and control. I bought my HPIL module with the Extended I/O module already built into it. The Extended Functions/Extended Memory module (which is already built into the 41cx, along with the time module, text editor, and a couple of other things you couldn't get on a 41c or cv) helped too. Then I got a combined double Extended Memory module. Extended memory works in files. Many modules made certain jobs easier that were already possible without them though. For example the first piece of equipment I ever interfaced my 41 to (besides the printer and tape drive) was the HP3421A data-acquisition unit for which there was an HP-41 module but I just looked up the 3421A commands in the manual and never bought the module. Later I interfaced the 41 to relay matrices, DMMs, signal generators, etc..
For the 41 to interface to RS-232, you use the HP82164A or FSI164A HPIL-to-RS232 interface converter. The latter came with two serial ports standard, and optionally up to eight, and of course HPIL allows lots of devices to be connected at once, meaning you could have even more if you wanted. I interfaced my 41 to IEEE-488 with the HP82169A HPIL-to-HPIB interface converter, and to parallel with the HP82165A HPIL-to-parallel interface converter. I'd say the 41 was way ahead of the 50 in real-world interfaceability.

Cool. Thanks Garth for the updates. Keep this up and I just might go dust off my 41 from storage, get an HPIL module for it and a few interfaces for it. I probably spent too much time with synthetic programming and missed all the literature on the interfaces available for it (it's been too many decades). <grin>