Commodore Peripheral Bus: Commodore DOS

From a device’s point of view, the layer below, layer 3 (“TALK/LISTEN”) defines the following:

The Commodore DOS API defines the meaning of channel numbers, channel names and the data traveling over channels in the context of disk drives. Communication to Commodore DOS happens through 15 data channels and one command channel:

Channels 0 to 14 need to be associated with a name and are used for the transfer of raw data like file and block contents. Commodore DOS does not specify a maximum size for disk or file names, but the limit for all Commodore and CMD devices is 16 characters.

Source: www.pagetable.com