About displays



#2

There have been several threads about displays. I want to ask if anyone knows why are the characters in the displays slightly slanted to the right? I can only think of the 71B which has "squared" dot matrix characters. Are easier to manufacture, or is a question of readability, or ...


#3

As far as I know, there's no justification for the slant other than aesthetics. English is written from left to right, so when one writes by hand, letters and numbers tend to slant to the right. I suppose this may have been the reason. I also suppose that if the Arabs had designed the first calculator, digits would tend to slant to the left. 8^)

Be that as it may, more modern calculators using dot-matrix displays have strictly vertical characters (no slant), such as the 28, 48 and 49.

-Ernie


#4

Ernie> English is written from left to right, so when one writes by hand, letters and numbers tend to slant to the right.

Unless you're left-handed. (Not that there's anything wrong with being left-handed %^)


#5

What REALLY bites is being a left-handed typist. ;-)

I cannot speak really about the slant of characters-- it seems to me just a decision intended to make the characters seem more "natural" and less machine-like to an audience used to the slant of English handwritten characters. In a world-marketing view nowadays, that's probably less "cricket" than it used to be. ;-) {But thank goodness nobody yet has made the decision to display characters with the least significant digits on the left...}

I will tell you about left-handedness...

My second-grade english/writing teacher used to whack my left hand with her ruler whenever I picked up a pencil in my left. As she told my parents, "it's the mark of the devil".

Aw, I got over it, and I'm still a Lefty despite all the row. My handwriting skills, to this day, approximate those of a rabid squirrel on crack; but hey, it suits my personality. :-D

Needless to say, I had much opportunity to display the marks of the devil to my Drafting teacher in eighth grade. The tendency of a lefty is to drag the ham-end of his fist across every line he draws, leading inevitably to a grey pallor cast over the whole vellum.

Combining that with my lettering skills, lack of math savvy, poor grasp of proportionality, and my tendency to overwork every portion of the drawing, I was able, over the course of a semester, to convince him that early retirement was a viable option.

The great equalizers, of course, are automated tools. Typewriters and word-processors now help me write, and calculators and computers help me do maths I'd be helpless to do on my own. Even me, ME! who art teachers assessed had only the talent to clean brushes, issue aprons and sharpen pencils, has MADE A LIVING from time to time using tools like Illustrator, CorelDraw, Photoshop and such.

Yeah, a mouse makes EVERYONE equally lefty/klutzy. MuuuHahahaha.... <revenge at last!>

And, yeah, on my 15c, I *DO* have to move my hand out of the way a lot, to see the screen. I wouldn't trade it away, though; it's my daily tool-- I have come to feel it is like an extension of myself.

I have half a dozen "standard" calculators at my office, none of which I like. I love all my HPs, though, and the 15c is just too "handy" not to keep within arms reach. (Well, I could have probably made use of an 11c just fine-- I never really have used matrices or complex numbers.)

But dangit, when oh when will American cars come equipped with a lefty-compatible drink-holder? Those stupid things that clip onto the window-sill are just a crime...


#6

Quote:
Combining that with my lettering skills, lack of math savvy, poor grasp of proportionality, and my tendency to overwork every portion of the drawing, I was able, over the course of a semester, to convince him that early retirement was a viable option.

8^)

Quote:
The great equalizers, of course, are automated tools. Typewriters and word-processors now help me write

QWERTY keyboards overwork the left hand (when writing in English) because the most commonly used letters in English are all on the left half (E, T, S, C, etc.) The Dvorak keyboard layout purportedly solves this problem -- among others. I wouldn't know, though; I've never used Dvorak, and am not inclined to learn it.

Quote:
Yeah, a mouse makes EVERYONE equally lefty/klutzy.

Why's that? I'm right-handed and my mouse sits comfortably to the right of my keyboard, where I can use it with the right hand. I'd say that the opposite is true, particularly in those keyboards/trackball combinations; the trackball is always on the right side and, being one piece with the keyboard, you can't rearrange things to left-handed nirvana.

My sister is a lefty, but she can write (more or less) with her right hand as well. She too suffered from uninformed teachers during childhood. What astonishes me is that she can write with both hands at the same time, going in opposite directions: left-to-right with her left hand, and right-to-left with the other one... you know, mirror-image-like. I've tried it a number of times, and never get the hang of it.

-Ernie (dekstrulo)


#7

Of course a mouse does not care if you are righty or lefty. I use a mouse, and it suits me fine as a lefty.

I am speaking of the spastic decoupling of hand and screen and eye and ball on desk, that unique artifact of using a mouse freehand that makes most everyone look drunk until they learn the more automated features of their drawing programs.

Get ahold of a PDA with the stylus, and draw the outline of your state or country in its paint program. Now go to your desktop PC, and sketch the same using the mouse. You are decoupled, pointer and image, and that alone is a handicap. Lefty or righty, the mouse drawing will be MUCH harder to do well.

#8

good theory! add to that the fact that HP machines display on the left and not right (like japanse).

#9

Julian:

I think that the slanted digits are a leftover of seven-segment displays, used in the '70s (such as the Monsanto MAN 1, or the diminutive MAN 3, or Litronix models). Some numerals are more readable with a little slant (specifically, the 7 digit), I think it is an aesthetics issue. BTW, I think the slant is specified as 10 degrees in some display spec sheets.

The slant may also came from CRTs used as numerical displays (i.e.: HP 9100); in such case there may be issues about the electron beam sweeping pattern, which may contribute to the slant. But I am not sure.

In my article in the Memories forum (I know you read it some time ago), there was a reference about unusual patterns on seven-segment displays on those years (i.e.: the Casio Mini-6 calculator with green fluorescent display). However, while the patterns were made to make them distinguihable even after a one-segment failure (sort of a Hamming distance analysis to cope with one-bit errors), some confussion was still possible.

RCA Numitron tubes (circa 1974) adopted a non-slanted, seven-segment pattern. They were an alternative to the classic and very nice (but older) Nixie tubes, with ten individual digit-shaped cathodes. Nixies used high voltage (170 V), but Numitrons were low-voltage devices.

Back to LED displays. On the opposite side from seven-segment, dot matrix displays from the '70s (such as the Monsanto MAN 2) were not slanted, either. But the electronics needed to drive them were expensive, using a ROM to encode ASCII patterns; and also multiplexing was mandatory. The seven-segment displays were easy to drive with cheap TTL parts like the 7447 (for common anode displays)or 7448 (for common cathode); and multiplexing was just an option. There was an issue of Popular Electronics magazine (between April and July 1974), in which a MAN 2 hobby project, which linked a full-size keyboard with a SINGLE CHARACTER MAN 2 display deserved the magazine cover!

Edited: 17 June 2003, 4:41 p.m.


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-21 displays all zeroes Barry Smith 5 355 01-27-2012, 01:22 PM
Last Post: Steve Simpkin
  Equivalent generic part # for HP cold-cathode displays... Nick de Smith 0 158 09-22-2011, 03:29 PM
Last Post: Nick de Smith
  HP-25 displays "Error" when trying to input numbers Harald 2 213 01-23-2011, 06:30 AM
Last Post: Harald
  HP 48gII displays division as a fraction Peter Klein 5 392 04-10-2010, 05:32 PM
Last Post: Peter Klein
  9815 A/S displays available! Joel Setton (France) 0 165 02-24-2010, 03:50 PM
Last Post: Joel Setton (France)
  OT: Phosphor Watches - E Ink Displays Gerry Schultz 14 743 01-06-2010, 12:05 AM
Last Post: Michael Plant
  Classic LED displays John Robinson 5 353 10-10-2009, 01:19 PM
Last Post: Joel Setton (France)
  LCD displays life expectancy hecube 10 625 10-06-2009, 12:04 PM
Last Post: Martin Pinckney
  HP LED displays Richard Ottosen 12 716 05-18-2009, 07:37 AM
Last Post: Andrés C. Rodríguez (Argentina)
  my HP 41cv displays a comma rather than a decimal?? Eric Mann 3 308 06-26-2008, 11:10 AM
Last Post: Eric Mann

Forum Jump: