rgb_video_card

Logisim RGB video component with a character generator ROM.

This graphics card is an Arduino like LCD. The display is 128x64 pixel dots.

Each character makes up 5 by 8 dots, Hence the aspect ratio is 21:7 (with padding on each side).

Customizable character set. Mine is surely awful. Generate your own char set here. Make sure to use hex values.

CGROM

The Character Generator ROM is pre-written with Upper case alphabet A-Zand numerical 0-9.

To display a char, simply address the ROM with the char ASCII code.

Eg:

0x41 is for the letter A, 0x30 is for 0 and so on.

Built-in cursor management:

The aspect ration is 21 by 7. So on the x axis column, you can display 21 char (0 to 20) and on the y axix row, 7 char (0 to 6).

Simply set the desired cursor position (x, y) and address the cgram to display the desired char.

At the end of a char fully displayed, a stop flag is raised and need to be cleared reset pin of a register. Simply write 1 and 0 (push button like) to start displaying new char again.

Clear pixel

Simply write monochrome 4-bit color code 0000 to overwrite current pixel with black color. Different colors can be used depending on the color code 1

Missing features

• Clear portion of the display
• Lower case ASCII char
• Support for extended ASCII char
• Punctuation char
• Use RGB colors (monochrome 4-bit in use as of now)