TSR - Terminate and Stay Resident for fx-9860G
It is possible to write an addin (in C / asm), which cooperates with CASIO basic interpreter.
This allows following features:
-
Data interchange between TSR and program in basic script
-
Possibility to extend basic by new commands
-
"?" command may have timeout, after which it returns default falue
-
Graphics acceleration
-
Raw HW access from basic script
I wrote simple program, which demonstrates this ability.
Please take it more as a proof of concept than as a complete solution.
I hope another developers use this idea.
Program behaviour:
The program goes to programming mode (Menu-B), creates a new file "TSRDEMO" and writes simple script here.
Then it exits the editor and run this script. To make the whole thing more cool it scrolls the screen.
You may press [Menu] and you will see scrolling menu screen:
Please do not activate another menu items now, TSR would crash.
To quit scrolling press [EXE]. This deactivates TSR addin. Now you can use any menu application.
Note: if you want to run it again, please delete "TSRDEMO" script first
TSR addin was tested in CASIO SDK (runs slow) and fx-9860G SD with fx-9860G II firmware (runs normal).
Detailed description:
Look the source code ;-). Main steps are:
-
Clear alpha variables and install timer with simple state machine
-
Call syscall App_PRGM (0x09F5), which hopefully lives in parent process
-
From timer: Replay keys by syscall PutKey (0x0910)
-
From timer: Scroll the screen and watch A variable, when it gets nonzero value, uninstall timer