sAPL - APL for Android 1.0.7

SAPL è un interprete completo per il linguaggio APL, ed è freeware senza pubblicità.

sAPL was originally developed by I.P. Sharp, in the mid-1980s, as a small workspace version of their mainframe APL product, but targeted to run on IBM P/C's. The maximum workspace size is roughly 300 kilobytes, but the code was taken directly from their mainframe 32-bit code, and was made to run on the IBM P/C platform, by means of an embedded interpreter. This made the product quite slow on the early 8080-based P/Cs, and it was not popular. A decision was made to offer sAPL P/C to any interested APL users, with a generous licence which allowed (and in fact encouraged) the product to be copied and distributed to anyone, without restrictions, with a view to encouraging use of the APL language.

The sAPL product offered here provides a full-featured APL programming environment, which despite the small workspace size, is capable of running a wide variety of usefull and educational real-world programs. And it runs on an Android platforms, at a speed now which is acceptable, given modern fast processors.

For now, this version of sAPL needs to run with the most excellent "Hackers Keyboard", which is available on the Google Play Store, and provides the full IBM P/C standard keys, generated correctly on an Android screen. In particular, the ALT key is used in conjunction with any standard text key, to correctly generate the APL characters. The "Hackers Keyboard" has over 1 million downloads, and works well with sAPL. We hope to update the "gKeyboard" (the Gemesys APL keyboard, which shows the APL characters with their text equivalents), but until that happens, I wanted to release the version of sAPL, because it performs well, calculates correctly, and provides a better user-experience than many other small-workspace APL interpreters. The APL session can be scrolled up and down using ALT-uparrow/downarrow, or paged up and down using SHIFT-uparrow/downarrow. This is very helpful when using a virtual keyboard on an Android tablet. Important hint: The "Hackers Keyboard", like "gKeyboard", needs to be check-box selected, and then also set as the default-keyboard, using Android "Settings" icon (the little gear icon). Once you have selected the "Hackers Keyboard", you can use its configuration features to squish it down, to 40% or 35% vertical height, so you have more screen real-estate to play with APL programs. This substantially improves the APL programming experience on a tablet, if you do not have a Bluetooth keyboard.

Currently, sAPL has been tested on Android KitKat (4.4.2), on Samsung Galaxy Tab series tablets, and earlier models. Please understand that this software is experimental, and is offered without any warranty of any kind.

There are no license restrictions with sAPL, and we are releasing it primarily for educational purposes, but there is nothing to prevent the use of this software for commercial purposes.

Enjoy holding an Amdahl-V8 mainframe equivalent in your hand, while you invert that matrix!

Mark Langdon,

GEMESYS Ltd.