Browse Prior Art Database

Decreasing TIME Interval Method for Accelerating Keystroke Action

IP.com Disclosure Number: IPCOM000046316D
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 3 page(s) / 18K

Publishing Venue

IBM

Related People

Murphy, AS: AUTHOR

Abstract

An accelerating mode of operation is described for the keystroke action on alphanumeric or text keyboards for display terminals. This gives increased user performance for such operations as cursor control, ruling and deleting characters, etc. Two different implementations are possible, the Decreasing Time Interval method and the Increasing Spatial Interval method. The former of the two is described herein.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 74% of the total text.

Page 1 of 3

Decreasing TIME Interval Method for Accelerating Keystroke Action

An accelerating mode of operation is described for the keystroke action on alphanumeric or text keyboards for display terminals. This gives increased user performance for such operations as cursor control, ruling and deleting characters, etc. Two different implementations are possible, the Decreasing Time Interval method and the Increasing Spatial Interval method. The former of the two is described herein.

In this method the spatial increment is held constant but the update interval is progressively reduced to a minimum limit value. The reduction of time interval is selected so as to give the appearance of a smooth increase in keystroke velocity on the screen. One choice is to make the increase in velocity linear with time, giving a constant acceleration. Thus on initial depressions of a key, a character is emitted from the keyboard and immediately echoed onto the screen. After a time interval (Il), provided the key remains depressed, then a second character is emitted. If the key is still depressed after a further interval (I2), then a third character is emitted. This is repeated for subsequent intervals I3, I4, I5, and so on.

For constant acceleration, the interval values should be chosen so that:

(Image Omitted)

Note: this is derived from:

S(n) = (Acc x T2)/2

Letting S(n) = kn

Therefore T(n) = K !n

and I(n) = T(n) - T(n-1)

where K and k are constants,

S(n) = Distance after n intervals

T(n) = Time after n intervals

Il corresponds to the conventional keystroke delay.

Some typical interval values are shown in the table below:

TABLE OF TIME VALUES FOR SUCCESSIVE INTERVALS

Interval Milliseconds

Number

1 400

2 166

3 127

4 107

5 94

6 85

7 79

8 73

9 69

10 65

11 62

1

Page 2 of 3

12 59

13 57

14 53

15 51...