It is user-callable via a jump table in RAM whose central (oldest) part, for reasons of backwards compatibility,[2] remains largely identical throughout the whole 8-bit series.
[4] The KERNAL was initially written for the Commodore PET by John Feagans, who introduced the idea of separating the BASIC routines from the operating system.
When Commodore technical writers Neil Harris and Andy Finkel collected Russell's notes and used them as the basis for the VIC-20 programmer's manual, the misspelling followed them along and stuck.
[7] According to early Commodore myth, and reported by writer/programmer Jim Butterfield among others, the "word" KERNAL is an acronym (or, more likely, a backronym) standing for Keyboard Entry Read, Network, And Link, which in fact makes good sense considering its role.
Berkeley Softworks later used it when naming the core routines of its GUI OS for 8-bit home computers: the GEOS KERNAL.
Indeed, the KERNAL proves much closer to the Plan-9 philosophy here, where an application would open a special "command" channel to the indicated device to conduct such "meta" or "out-of-band" transactions.
For example, to delete ("scratch") a file from a disk, the user typically will "open" the resource called S0:THE-FILE-TO-RMV on device 8 or 9, channel 15.
The most common device used, of course, is the floppy disk system, which uses a format similar to MD:NAME,ATTRS, where M is a flag of sorts ($ for directory listing, @ for indicating a desire to overwrite a file if it already exists, unused otherwise.