Tag: Modes

Keyboards and Keypads II

I had been searching for a good USB keypad for use with my laptop. I prefer to enter sets of numbers using a separate keypad rather than using the “keypad mode” keys native to my laptop, since I don’t need to keep switching between modes if I am both entering a list of numbers and going back and forth to text.

Over the years, I have had several different keypads, and the most common problem is that the rubber feet keep coming off of them. To anyone manufacturing these things, I need to tell you:

  • people who use separate keypads use them with their laptops;
  • this means that your keypad must be as mobile as my laptop;
  • when little pieces come off the keypad in my book bag, most likely one or more of the rubber feet, this causes the keypad to annoyingly rock side to side as I press the keys, since the pad is no longer supported in a balanced way;
  • this always happens, because manufacturers universally fasten the feet (which are made of rubber to keep the keypad stationary on the table as I type) to the keypad with glue;
  • this is a bad thing, because these feet eventually become un-glued;
  • there are many new keypad designs which come out every year, the prices of these differ wildly, as do their functions and capabilities;
  • all of these people glue the rubber feet to the keypad, regardless of how much you paid for the keypad;
  • meaning that all keypads from $6 to over $100 has a useable life of about 3 months, unless you wish to put up with the instability issue;
  • and so if you are like me and you get annoyed with it, you’ll spend $6.00 for a minimal USB keypad, knowing that you’ll buy one again in 3 months.

This is an open letter to the many manufacturers of such keypads: rubberize the entire bottom of the keypad. Affix it mechanically rather than with glue. Hell, you can even make the whole keypad waterproof. Even make the whole thing our of silicone like some manufacturers do with entire keyboards.

Above is a $6.99 keypad I picked up at Canada Computes, made by iCan. The depiction from the store website is more optimistic than my actual product, feet-wise. Notice that one piece of rubber goes all the way across the top. That would actually be nice, except that my actual keypad has the conventional four smaller feet. I am still hopeful that this one might be more durable, since they appear to be on the unit quite solidly. As a bonus, the USB wire wraps all the way around the unit when you store it.

Visits: 90

HP Calculator Annoyances II

I am as much of a fan of the RPN mode as anyone. But the implementation of RPN in the HP calculators have to keep up with new developments in technology.

For one thing, I had trouble in RPN mode, to make a list of random numbers. Suppose you wanted to make a list of numbers with a certain variability such as:

150 + 25*RAND

I would do this to generate a list of random numbers with a minimum of 150, and a maximum of 175. RAND is the random function which generates a number between 0 and 1. In RPN, I would need to enter 150 and 25 in a stack, then my RAND, then * and then +.  That generates one such random number. To generate more numbers, such as a list of 25 numbers, you need to go through the whole thing again, 24 more times. It may have been necessary 20 years ago to actually repeat the same keypresses over and over like this, but dual displays have been around for slightly longer than 20 years, making these operations a lot less error prone, and way more efficient.

You may do this calculation better in algebra mode, using the left arrow key to go back to the statement you typed in, then press ENTER to get the new number. This will cause fans of RPN to vascillate back and forth between algebra and RPN modes whenever they need to take advantage of certain features. It is likely that the official HP claim that RPN is more efficient with respect to key presses is becoming less and less true as technology improves, unless HP can figure out how to repeat a stack of numbers and operators.

More on this next Wednesday.

Visits: 97