A poket-to-laptop size microcomputer/programmable calculator, based on Arduino DUE and Terminal-BASIC
Here is a first variant of matrix keyboard. I choose 5x9 size as the smallest suitable to support full cyrillic charset and digits on separate keys (33+10).
It will use 2 shift keys: the red shift and the blue shift, which state will be indicated by the 2 LEDs of corresponding colors.
First prototype will consists of minimal number of modules:
The firmware is a Terminal-BASIC with UTFT output driver.
Things to be done includes support for double precision floating point arithmetics (DUE has double reals unlike 8-bit AVRs). and driver for a matrix keyboard of 45 - 48 keys.