Lavadeira.net has a long-run series of articles teaching C Programming for the MSX machines. These are the latest articles:
Functions. Declarations, definitions and externs. How to define functions that don’t take parameters. Functions declared locally inside other functions.
The MSX graphic characters and the 2-byte sequences to put them on the screen. Differences between the Japanese and European graphic character sets. Escaping single/double quotes and backslashes in order to print them from C programs.
Screen escape sequences: strings of characters that control aspects of the screen. Difference between C escape sequences, screen escape sequences and control characters. Using escape sequences to change the shape of the cursor, insert and delete lines of text, hide and show the cursor. How to create a text scroll upwards or downwards using only escape sequences.
Control characters, their functions and character codes. C escape sequences. How to print control characters that don’t have an escape sequence in C using the character code in hexadecimal or octal.
Lavadeira asks support via Patreon and if he gets enough support he will hire translators to proper translate the manuals to English.