What is KERNAL?

KERNAL (not kernel and all upper case) is the OS that has ran on Commodore home computers (micros) since the introduction of the Personal Electronic Transactor (PET) in 1977 although most of us only knew about CBM BASIC 2.0 running on ROM. At the time, most of us neither understood nor cared what an OS was. In general I wish I could say that I know more about KERNAL.

As with most programmers who liked Commodore machines, I started writing code on a C64 and this was my only exposure to its built-in language interpreter ( CBM BASIC 2.0) and its OS (KERNAL).

Commodore 64:

Although I enjoyed many hours of programming in CBM BASIC 2.0 including some machine language (lots of POKE calls) on my C64 (1982-94) not any other language, I now wish I knew then more about the OS underneath CBM BASIC 2.0. Hence the only time I truly interacted with the OS was while programming CBM BASIC 2.0 — in other words, merely basic code poking into the OS. At least, those hours of programming had me in front of my C64 connected to a cassette recorder and a B/W 13" Zenith TV set with a broken channel potentiometer (pot or knob) via an RF modulator on channel 3 (still no over-the-air channel 3 where I live), a container of dry-roasted peanuts and a three-litter bottle of soda. At times, given the fact that my memory has flushed out almost everything I learned in CBM BASIC 2.0 more than three (3) decades ago, I wonder if I should once again learn how to program in CBM BASIC 2.0 accessing KERNAL with machine language as I used to do or perhaps this time writing directly to KERNAL in assembly.

Although the original C64 has not been in production for almost three (3) decades, this has not stopped developers from working on new technologies retrofitted printed circuit boards (PCBs) to emulate hardware like FDDs, HDDs, modems and even NICs to access local networks or the internet. The same is true for new OSs as replacements for KERNAL — not to mention releasing new games for that matter.

• Advanced Computing Environment 128/64 (ACE-128/64) by Craig Bruce comes with Unix-like shell. It needs a RAM Expansion Unit (REU) up to 16 MB, a RAMLink storage device up to 16 MB, a Creative Micro Designs (CMD — not to be confused with CMD.EXE as in command prompt) disk drive and other hardware needed for specific jobs. From what I see, this replacement OS might be the best in this short list.

• Asterix by Chris "Pollar" Baird was "An experimental UNIX-ish operating system for the STANDARD Commodore 64" released in 1991.

  

• CP/M Cartridge was released in 1983 by CBM with Z80 running at 3 MHz CPU — almost twice faster than the 1.023 MHz MOS Technology 6510 in the C64 with a second Z80 CPU and CP/M 2.2.

  

• DOS/65 by Richard Leary offers file system compatibility to CP/M-80 for the C64 "in order to make any 6502 system a truly workable disk based system [with] a degree of compatibility now possible not only between 6502 systems but with large parts of the world of CP/M systems" (09/2009). Note that the developer has posted lots of documentation how the DOS/65 works in detail. Aside from being able to learn about the 6202 architecture, you can learn how an primitive OS can be developed or how it works.

  

• JiffyDOS KERNAL ROM Overlay IC (simply referred to as JiffyDOS) provided a DOS-like environment for the C64 and C128. Aside from offering better access to floppies, it also added extensions to CBM BASIC 2.0 — DOS Wedge (LOAD "C-64 WEDGE",8).

  

• GeckOS/A65 is a "full-featured Multitasking/Multithreading operating system for the 6502... preemptive and implements some for Unix-like features, like signals, semaphores, relocatable fileformat, standard library, internet support via a kind of simplified sockets and last but not least virtual consoles" (Jun. 2020).

• Other Operating Systems (GEOS) by Berkeley Softworks was released in 1986 as a replacement for KERNAL and offered a GUI — a ground-breaking feature at the time. Refer to more detailed information in the Other Operating Systems page.

  

• LUnix (now LUnix Next Generation or simply LNG) by Daniel Dallman and others is an "operating system for the Commodore64... [that] supports TCP/IP networking (SLIP or PPP using a RS232 interface)... [with] look and feel like UNIX" (08/2013). Note that the RS232 (Recommended Standard 232) standard is for data transfer using serial ports commonly used in modems — in other words, network access.

  

• WiNGs by Jolse Maginnis is a 16-bit and multi-tasking OS for the C64 and C128 with optional packages for the GUI, shell consoles and internet access. WiNGs needs a CMD SuperCPU (W65C816S 8/16-bit processor), CMD SuperRAM card with at least 1 MB, a CMD HD (if not a CBM 1351 floppy drive), IDE64 (SD external drive instead of a CMD HD), a CBM Mouse 1351 mouse for GUI, a CMD Turbo232 DUART cartridge and a Swiftlink or IDE64 DUART full duplex asynchronous communication (modem) for internet access (02/2020). WiNGs seems to be the most interesting OS in this short list, but all this hardware seems a bit too expensive for my taste. If you start buying all the extra hardware to operate a C64 as modern machine, you might as well get a new computer.

Aside from OSs, there is also the OpenCBM project, which is a "Win NT/2K/XP, and Linux/i386 kernel driver and development library to control serial CBM devices, such as the Commodore 1541 disk drive, connected to the PCs parallel port via a XM1541 or XA1541 cable. Fast disk copier included. Successor of cbm4li" (06/2006).