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3.5" Swap Discs

PostPosted: Sun Mar 01, 2020 8:06 pm
by Bob_C
I think these 5 discs were originally purchased from Educalc and possibly used to emulate an HP-41. Has anyone heard of them?? These discs have hundreds of files for the HP-41, HP-71 and HP-75

Re: 3.5" Swap Discs

PostPosted: Mon Mar 02, 2020 1:27 am
by Garth
You don't give any info on them. I looked in my old EduCalc catalogs hoping to find such a set of discs, but without success. Are you hoping to buy, or sell? If sell, what's on them? I never did get the HP-IL disc drive, only the microcassette drive; but it'd still be interesting to know. If you sell, it would be nice if you printed out the programs and supplied them to Warren to post here on the website, or just loan him the discs. I have two 71's, a 75, and a 41cx. I use the 41 every day. I rarely use my 71's. I have only used the 75 enough to verify that it works, but I've never actually used it. Someone gave it to me used and very beat up.

Re: 3.5" Swap Discs

PostPosted: Mon Mar 02, 2020 6:57 am
by mike-stgt

Re: 3.5" Swap Discs

PostPosted: Mon Mar 02, 2020 7:22 am
by Garth
That looks excellent! Thanks, Mike! I bookmarked it.

I might comment that the first one I looked at there was about the 71 having amnesia. My friend who got me into the 71 (after the 41) pulled his 71 out of his attache case in my presence one time and there was a reset or memory-lost condition, and he speculated it was because of keys getting pressed in the attache case. So after I had the same problem a couple of times after I got mine, I had a woodworker friend make me a little wooden box with one end open, just big enough to fit the 71 with its soft case into, with all the QRGs in the case. It would slide in and out freely but not have any extra slop. The purpose was too keep keys from being pressed in the attache case. I never had the problem again. That was probably 30 years ago. As for the 41, I have never had a MEMORY LOST condition outside of my own blunders when I was new to synthetic programming. I got a ZENROM module cheap though when they were being closed out, which makes all the synthetics direct-key-in like they were not synthetic at all, so I no longer needed the byte grabber.

Re: 3.5" Swap Discs

PostPosted: Mon Mar 02, 2020 9:29 pm
by mike-stgt
Garth wrote:That looks excellent! Thanks, Mike! I bookmarked it.

The site was new to me too, I found it by entering few key words in a search engine (no, the other one, 4-letter-named, starts by B-, ends on -ing).

Now -- vast subject drift, absolutely nothing to do with "Buy&Sell", but an attentive content manager might find the correct rubric to file it -- within that a. m. HP Handheld Conference 2014 gleanings I found a comparison of four solutions of the same task on different machines with different programming languages. (There are only the slides without notes, no hint about the conclusion.) Mission: for numbers A and B (input) compute (A-B)/B and (B-A)/A and show output as %, positive value first or 1st on stack.
The shown solution for HP41 on page four looked a bit too long (almost 'spaghetti') to me:
Code: Select all
 01▶LBL "PCH"
 02 X>Y?
 03 X<>Y
 04 %CH
 05 X<>Y
 07 X<>Y
 08 %CH
 09 X<>Y
 10 RDN
 11 END

I suggest (two lines less but only one byte shorter):
Code: Select all
 01▶LBL "WTF"
 02 RCL Y
 03 %CH
 04 RDN
 05 %CH
 06 R^
 07 X<0?
 08 X<>Y
 09 END

I assume that over time I am for sure not the first who found a shorter way to achieve the goal. So this append is just for the record: I also done it.

Re: 3.5" Swap Discs

PostPosted: Wed Mar 04, 2020 3:43 pm
by rprosperi
I like your "WTF" program, something satisfying about XEQ "WTF"...

The purpose of this presentation was simply to illustrate the drastically different programming languages and paradigms in 4 generations of HP calculators, the 41C, 71B, 50g and Prime.

Joe's comments when presenting this was that the programs presented (especially the 41C) were not optimized and that he expected more people would comment on how to improve/shorten the sample code than comment about the comparison. I think you have fulfilled his guess. LOL