UltimateCLI

A small shell for your Commodore 64 and Ultimate

Browse directories, read text files, mount disk images, and launch programs—all from a familiar command prompt on your C64.

UltimateCLI is a lightweight, Unix-inspired shell for the Ultimate 64 and Commodore 64 equipped with a 1541 Ultimate. It brings command-line convenience to the Ultimate filesystem while keeping the classic C64 screen and keyboard experience.

Features

• Browse your files — list directories, filter filenames with * and ?, and navigate with cd.
• Read text and sequential files — use more for paginated viewing, with ASCII and PETSCII support.
• Launch programs — start PRG and CRT files directly from the Ultimate filesystem.
• Work with disk images — mount and unmount images on drive 8, list their contents, and load programs.
• Manage files — copy, move, rename, delete, and create directories.
• Filename completion — press CTRL + I to complete names in the current Ultimate directory.
• Command history — use cursor-up/down to recall your last eight commands.

Requirements

• An Ultimate 64, or a Commodore 64 with a 1541 Ultimate
• The Ultimate Command Interface enabled in the Ultimate settings

PRG launching and normal filesystem commands do not require networking. CRT launching and automatic home-directory lookup require the Ultimate’s network connection and REST service, with an empty Network Password. CRT launching requires firmware 3.11 or later.

Getting started

Load and run ultimatecli.prg, then type help.

On a standard C64 keyboard, CTRL + I acts as TAB for filename completion.

Development status

UltimateCLI is under active development. CLI regression tests run in VICE on both PAL and NTSC configurations, but VICE cannot emulate the Ultimate hardware APIs. Hardware compatibility testing is ongoing.