Jörg Wolfram has been developing interesting project so called AVR-ChipBASIC on Atmega32. Simply speaking this is a basic language programmable chip computer which his capable to run basic programs and with ability to display results in RGB TV screen.
This is almost fully functional computer system that have many functions including:
RGB-TV 23 rows with 30 colums, NTSC/PAL per jumper selectable;
prepared for FBAS encoder;
256 characters with pseudo-graphics, 8 colors;
simple sound (1 channel, 1 voice, noise);
serial port (1200Bps only) with charge pump;
parallel printer port, also usable for IO and ADC;
I2C-port for data EEPROM and temperature sensors;
ISP port is also able to handle Atmel dataflash;
mostly Tiny-BASIC compatible with many improvements;
4 programs to 51 lines are stored in flash;
built-in full screen editor;
serial load/store via text transfer, listing print;
integrated monitor with single step, breakpoints.
Programs can be edited and run directly on TV screen and run from AVR chipbasic menu system. Also program can be saved, transferred via terminal or even printed. Firmware is updated constantly so newest version of project can be downloaded here.