Commodore 128 BASIC 80-Column Display Command

The Commodore 128 features a unique dual-display architecture that allows users to switch between 40-column and 80-column modes directly within BASIC. This article provides a concise overview of the specific command required to activate the 80-column display, explains the syntax variations for text versus bitmap modes, and details how to return to the standard 40-column screen. Understanding this command is essential for developers looking to utilize the full potential of the C128’s VDC chip for enhanced text visibility and programming workspace.

To switch the Commodore 128 to the 80-column display mode while in BASIC, you must use the GRAPHIC command with specific parameters. The primary command to enable 80-column text mode is GRAPHIC 0,1. When executed, this instruction tells the system to utilize the Video Display Controller (VDC) chip rather than the default VIC-II chip used for 40-column output. This switch provides a wider screen real estate that resembles modern PC terminals, making it ideal for word processing, spreadsheet applications, and coding longer lines of BASIC programs without wrapping.

It is important to distinguish between the available graphic modes when using this command. While GRAPHIC 0,1 activates 80-column text, entering GRAPHIC 1,1 will switch the display to 80-column high-resolution bitmap mode. For most standard BASIC programming tasks, the text mode (GRAPHIC 0,1) is the desired configuration. If you wish to return to the default 40-column display mode found on the Commodore 64, you simply need to type GRAPHIC 0. This command resets the video output to the VIC-II chip, restoring the classic blue screen environment.

Utilizing the 80-column mode requires a monitor or television capable of displaying the RGB or composite output from the C128’s 80-column port. Once the GRAPHIC 0,1 command is issued, the cursor will appear on the new screen, and all subsequent BASIC input and output will occur in the 80-column format. This flexibility was a key selling point of the Commodore 128, allowing it to maintain compatibility with C64 software while offering enhanced productivity features for business and development tasks through simple BASIC commands.