Version 1.1.0 finally made it onto the App store. So, what am I to do now? Update the app yet again I guess.

I've already started (and nearly finished) a minor update, 1.1.1, that adds 2 additional scales (KZ and T₂, fundamental scales folded at 360). Additionally, I've went in and added gauge marks on some of the scales for some key values...

On the CI, KZ, T₂, C, and D scales, I've added gauge marks at 12 and 144.

On the C and D scales, I've added C and C' gauge marks at √(4/π) and √(40/π).

On the C and D scales, I've also added a p gauge mark at π/180, a p' mark at (180*60)/π, a p'' mark at (180*60*60)/π, and a p⁰ mark at 180/π, and a mark on the C scale only, at (200*100*100)/π.

Additionally, on the A and B scales, I've added gauge marks M at 100/π, and π/4 marks.

I also updated the documentation with the new scales, and added a "clear" cursor option (I don't really care for it too much, but there it is...), and I "tweaked" the timing on some of the touch-associated motions (like the delay for single-tap vs double-tap recognition to avoid moving things by 1 pixel when a slide scale change is really wanted...)

I should be sending this update out fairly soon, after I get done running my checks on it to ensure everything works.

Yesterday, July 31st, I released version 1.1.0 of the iSlideRule app to Apple for review. Hopefully, if all goes well in review, the update will be available within the next week.

It's been quite a while since I had done an update (November of 2008 was the last update). This update includes a lot of changes from the previous version, mostly based on feedback from customers.

I've provided a means via the Settings application to specify the order in which to place scales. This was a prime issue in earlier versions and one I had to address.

I've also added what I think is a unique, educational aspect to the app; it can display a numeric value on the cursor that represents the value on each visible scale under the hairline. Of course, there is an option in Settings to turn this off.

Another new feature is double-tapping the scales. There are now three sets of four scales for each of the rules, and slider. This gives an effective 36-scale slide rule. Scales are selectable from the Settings application. Double-tapping each rule or slider changes the scales to the next set.

Single-tapping the rules or slider moves the opposite 1 pixel for fine-tuning of position. And this brings up something that people need to realize about slide rules, and slide rules on digital devices...

The scales in iSlideRule are 1964 pixels wide (32 pixels of "white" space on either end). So, the "C" scale for example has 1900 pixels between 1 and 10. This means, from a calculation standpoint, that there are only 1900 unique numbers available between 1 and 10. On a "real" slide rule, the user would "guess" or estimate position and value visually; mid-way between two "ticks" would be visually interpreted for value.

In iSlideRule, since there are limited locations for "ticks", if they were drawn in a distinct line, some scales would have ticks that would be four, then five, then four, pixels apart, and would have an uneven distribution.

When generating scales for iSlideRule, I took an approach wherein I generated the scales at 4x the size I needed, then reduced them to the final size with anti-aliasing. So; I get scales wth ticks that appear evenly spaced, however they are a bit "fuzzy" or blurred. It's still up to the user to visually interpret the position of the hairline over the values to come up with the answer. This was my solution to how to represent an "analog" device such as a sliderule, on a digital platform; while providing as close to a real, useful tool, as possible.

By the way, another new feature on iSlideRule is the "flip view", accessible from the main, portrait orientation by pressing the little "info" ( i ) button in the lower right of the display. This will bring up a simple quick guide that covers configuration and settings, gestures and usages, and short details on all sixty of the available scales (yes, I also update the scale selection from 40 to 60 in this release).

I hope everyone enjoys the update as much as I enjoyed spending time creating it!

-Steve

There are many features that I plan on updating and/or adding to iSlideRule over the next weeks and months.

Primary among the features list that I'm planning and working on is moving the configuration and settings into the application so that scales and color can be updated while the application is running. In addition, I'll be adding a feature that will permit positioning of the scales on their individual slides. Settings will be accessible from "portrait" viewing mode via a control present on screen to flip the whole view over.

Another feature that will be added will be a flip-side view of each slide and rule with additional scales. Unlike a normal slide rule however, that has two sides, each slide will have three sides (think triangular engineering and/or drafting rulers), with 4 scales each (12 scales possible on each bar), and each one can be "flipped" independently of the others. I've got an approach that allows me to use up and down swiping on the rules to perform the flip, and flip to the appropriate view.

Lastly, of some use to those that have a hard time reading the numbers and ticks on the rules, I'll be adding a selectable feature to have the current viewable scales values shown on screen (in portrait mode, they'll be shown below the bars and labeled. In landscape mode, while I haven't completely settled on the approach, they'll probably be displayed, after a slight delay, on top of the cursor, in a semi-transparent way, and disappear while moving the cursor.