P→R, R→P, Vector Arithmetic and HP-35

[Matt Agajanian]

Hi all.

Yeah, Bill Hewlett wanted a shirt-pocket HP-9100.

Yes, Polar & Rectangular conversion can be done with trig & square root combinations. But if the objective was to put a 9100 in a handheld, why were polar/rectangular conversions omitted?

Yeah, I know. The team had 768 bytes to work with.

[Steve Simpkin]

Yes, "Time is short and ROM is full" really applied back in 1971 when they were pushing the state-of-the-art to develop the HP-35. Add to that the question of whether enough people would pay the princely sum of $395 to replace their $25 slide rule to make the project profitable. And if, for some reason, the HP-35 was a success, there would always be the opportunity to sell an improved model.

[Matt Agajanian]

Yeah, I get it.

Let’s see if the crowd will go for an electronic slide rule first. Then, we could later build on that for an encore. And, if so, it wouldn’t be long before we (HP
engineers) would be presented a big brother to the 35. Yeah, I see.

[brouhaha]

(07-05-2024 04:57 AM)Matt Agajanian Wrote:  Yeah, I get it.

Let’s see if the crowd will go for an electronic slide rule first. Then, we could later build on that for an encore. And, if so, it wouldn’t be long before we (HP
engineers) would be presented a big brother to the 35. Yeah, I see.

The hand calculator probably had explicit approval from Bill for the HP-35 feature set as an stepping stone, having a plan from the outset of how to advance from that to a more 9100-like calculator, which of course was the HP-65, delivered in lesst than two years after the HP-35.

The HP-45 was another step along the way, and the HP-80 was an interesting side-path, with financial calculators becoming a really big business for HP as well.

All calculators after the 35 and 80 were dependent on a newer "quad ROM" chip that provided 1Kx10 instruction memory, rather than the 256x10 of the original ROM. Even _with_ the new ROM, cramming everything necessary into the HP-65 appears to have been quite a challenge.

[Matt Agajanian]

In any event, HP did it. In getting it done, they developed another groundbreaking engineering feat—the handheld programmable calculator, the 65, that was so revolutionary it even proved crucial and essential on some NASA missions and spacecraft!

[Gene]

But if you knew the answer in advance - and that was the answer - why ask it as a question?

Rather think through these points and perhaps rephrase it more like this:

“Since the rom capacity of the HP-35 was so limited, I had never realized that functions X Y and Z were left out from the 9100 function set!”

That is better than questions similar to previous ones where you already know the answer?

Then perhaps follow up question or two like these:

Which function do you think was the last one included ?
And
Which was the first one left out?

But asking the question as you did will make people not engage the discussion as they might have because it sounds repetitive to previous questions where you know the reason.

Offered to improve the abilities to foster discussion.

[Matt Agajanian]

I felt that asking the question in the form I did would beneficial. I was looking for explanations why since a handheld 9100 was the objective and the fact that polar/rectangular conversions were not included on the 35. I posted here since this group would shed some light on my question.

[Maximilian Hohmann]

Hello!

(07-06-2024 04:47 AM)Gene Wrote:  “Since the rom capacity of the HP-35 was so limited, I had never realized that functions X Y and Z were left out from the 9100 function set!”

Maybe the more sensible question to ask in this context (which has of course been asked a dozen times already...) is: "Why did the 35-year-celebration model HP-35s, which has plenty of rom capacity and display and keys and everything, still not include polar/rectangular conversion keys?"
Instead of adding fancy stuff like ALG mode they could have taken the opportunity to finally create the shirt pocket sized HP-9100 that the original HP-35 was supposed to be.

Regards
Max

[Jake Schwartz]

Hi
With regard to a "handheld 9100", in the Q&A portion of the HP handheld conference where Dave Cochran attended and spoke, I actually asked whether the goal was originally to have the HP-35 be programmable and Dave said no. This seemed puzzling to me, since everyone had heard that Bill Hewlett originally fantasized having the 9100 miniaturized into pocket size. Perhaps they understood early on that the technology wasn't nearly ready for such a major leap in the 1971-72 timeframe.

Jake Schwartz

[Matt Agajanian]

(07-08-2024 05:31 AM)Jake Schwartz Wrote:  Hi
With regard to a "handheld 9100", in the Q&A portion of the HP handheld conference where Dave Cochran attended and spoke, I actually asked whether the goal was originally to have the HP-35 be programmable and Dave said no. This seemed puzzling to me, since everyone had heard that Bill Hewlett originally fantasized having the 9100 miniaturized into pocket size. Perhaps they understood early on that the technology wasn't nearly ready for such a major leap in the 1971-72 timeframe.

Jake Schwartz

Thank you, Jake for that. Definitely illuminating and helpful.

[Andres]

Just a minor detail: IIRC they had 768 10-bit words for firmware, so it's more like 960 Bytes. Of course, it is incredible they did so much with so little resources!

(07-05-2024 04:41 AM)Matt Agajanian Wrote:  Hi all.

Yeah, Bill Hewlett wanted a shirt-pocket HP-9100.

Yes, Polar & Rectangular conversion can be done with trig & square root combinations. But if the objective was to put a 9100 in a handheld, why were polar/rectangular conversions omitted?

Yeah, I know. The team had 768 bytes to work with.