How RAD is that!?

[Matt Agajanian]

Hi all.

Yeah. I could hear it already, the cost, the RAM limitations, incorporating the amount of quads needed would skyrocket the 35’s price to an unreasonable level in addition to being technologically out of bounds. Converting between degrees and radians is just a matter of multiplying/dividing a conversion factor.

In any case, I’m just gonna ask.

In the sciences, I would presume radians are used more often than degrees. Degrees are more familiar than radians (you know what I mean). Degrees mode trig function would make the 35 more marketable, accessible, and familiar for any & every buyer of a 35.

So, humor me on this. What would be the development, marketing, technical, and other ratifications if HP were to feature both degrees & radians on the HP-35?


Yeah, TI made what I’m describing feasible and actual with the SR-50.

[brouhaha]

(06-04-2024 07:09 AM)Matt Agajanian Wrote:  So, humor me on this. What would be the development, marketing, technical, and other ratifications if HP were to feature both degrees & radians on the HP-35?

There was literally one a single 10-bit word of ROM left over in the HP-35. An entire additional ROM chip would have had to be added. That likely would have added $10 of production cost. More code development and test time. It's all but impossible to quantify the additional develoment costs, and even moreso the lost opportunity cost. And of course, there wasn't a leftover key or switch for the angle mode, so either an additional key or switch would have had to be added, or some existing key turned into a shift key, with all of the addtional ROM code, development time, and test time which that would entail.

Framkly, it's amazing that they managed to make the HP-35 and ship it in 1972 AT ALL.

There was plenty of time to come up with improved models with more features, and better accuracy, and they quickly did so.

If you had asked anyone involved in the HP-35 development whether having a way to switch between degrees and radians would be a good feature to have, I'm sure NONE of them would have said no. The essence of engineering is making tradeoffs. Anyone with the slightest modicum of talent could keep iterating, adding features forever. Someone has to make the decision as to what is the MVP (minimum viable product), so that there's a point at whcih the project can be done, and the product shipped, regardless of how many other nice-to-have features can be thought up.

The HP-45, introduced slightly over a year later, increased the ROM size by 167%, and no increased per-unit manufacturing cost (and possibly a decrease), because the MOS integrated circuit technology was advancing rapidly. They used 2.3x much ROM as the HP-35 for the enhanced caluclator functionality, and actually had a little room left over, in which they put the undocumented stopwatch. To this day, it is unclear whether the undocumented stopwatch had management approval as a way to test a possible future feature (which later made it into the HP-55), or whether it was just the engineers having fun with the leftover space.

Once again, with the HP-45, they could have spent more development time to make an even better calculator, but they wisely chose to ship with a relatively modest set of improvements.