Of Commodore

Replicated, corrected and reformatted from https://opencbm.trikaliotis.net/ on 7/16/2025

Courtesy of Zippy Zap @ Lemon64 forums: Has built-in function keys, uses wedge style commands with @ and >. so >$ is directory (or @$) > or @ reads the error channel. Does not have a fast loader. CommandAction@ or >Read error channel>$ or @$Load disk directoryLOAD”PRGNAME” (with or without ,8 or ,9)Load file from disk@8 or @9 Direct a command to the corresponding...

Today, we can change and swap the kernal about and try out new things a lot faster and easier than it used to be.

We'll go over the different levels of things that can be done, from experimenting with simple kernal code changes to options for swapping out the installed and in-use version!

[Archived from Peter Schepers' site]
The ROM's in the C64 and the original 1541 models are 24 pin and are not directly pin compatible with burnable 2732 or 2764 EPROMS. In order to upgrade to a newer ROM revision or change the ROM to something else and use either a 2732 (for the character set) or 2764 (for kernal/DOS) EPROM, a socket adapter must be built. See here for detailed instructions on how to build one.

Socket adapters are required on the original C64 and 1541 models when replacing the existing 24-pin ROM with a 28-pin EPROM, like a 2764 or larger. They are also needed if you want to replace a 2764 with a larger 27128, a 27128 with a 27256 or a 27256 with a 27512. All of these adapters are covered here.

This is a cool programming "framework" that was adapted for the C64, and was intended to allow programmers and users to easily create and use programs across multiple platforms freely.

f1: LIST: + CHR$(13)f2: OLD + CHR$(13)f3: RUN: + CHR$(13)f4: Toggles something? ON/OFF (maybe fastload?)f5: LOAD + CHR$(13)f6: SAVE”f7: @$* + CHR$(13)f8: LOAD + CHR$(13) I also found a couple more: CTRL + f1: @N* + CHR$(13)CTRL + f7: Disable Function Keys Now before you go pressing CTRL + F1 be warned, THIS WILL FORMAT THE DISK IN DRIVE 8, and give it a label...

Command Action @ Read the disk drive error channel @C:newfile=file Copy a file on the same diskette @I Initalize the disk drive @N:diskname,ID Format a NEW diskette @N:diskname Short NEW @Q Disable the JiffyDOS commands @R:[newname]=[oldname] Rename A File @S:[file1],[file2]... Scratch a file (files) @UJ Reset the disk drive @V Validate a disk @$ Display a disk directory @#device Set the default device number...

PiffyDOS – Programmers JiffyDOS JiffyDOS from CMD has almost become a de-facto standard for the Commodore world. It’s compatibility, speed and features makes it the natural choice for users today. I found it very interesting how CMD managed to squeeze everything into that 8kb of ROM and started to disassemble the code. With the Omicron re-assembler I got about 100k of text that i...

Prologic DOS and Prologic DOS Classic (version 1.6) was a quick loader that included a module on the 1541 floppy disk drive and a module for the user port or expansion port of the C64. The whole thing was connected via a parallel cable and supposedly ensured that an acceleration of 200 times the normal speed could be achieved. It was distributed by Jann...

Here is a curated list of known C64 kernal and character ROMs. The list will be updated whenever new information becomes available. Some require additional hardware or mods, some do not. Details are provided wherever possible.

Introduction============This is a modification of the Commodore 64 kernal with improved support for thewonderful SD2IEC device by Ingo Korb. Either burn the 8K kernal file to an EPROMand replace the original kernal ROM chip of your C64, or use a device that canoverride the kernal ROM (e.g. 1541 Ultimate, Turbo Chameleon 64, EasyFlash≥). Changes since 1.0:– the browser is started with F7 instead of...

Note: Instructions translated from https://www.c64-wiki.de/wiki/V-DOS Early EXOS and clones may be PAL-only.  They can be modified to work on NTSC systems by editing the binary directly: Search for: ad 00 dd 4a 4a ea ea  Replace with: ad 00 dd 4a 4a c1 ea Function key assignment To make the C64 easier to use, the most important DOS commands are stored on the function keys. Note:...

Thanks to SX64 Dot Net member hodo, here is info from the Datel instructionsheet. DATEL TURBO ROM IIReplacement Kernal ROM for Commodore 64 INSTRUCTIONS COMMANDS In the normal mode the command and operation structure remains unchanged.In the Turbo mode the new instructions are as follows:Disk LOAD, SAVE, & VERIFY are all automatically at Turbo speed. In addition thefunction keys are now: NUMBER CONVERSION f4:...

[Note]: I have edited this document substantially for formatting and spelling errors. I have also removed sections that talk about sending your hardware to a no-longer-existing business, because while I’m only doing all this for posterity and “love of the game”, somebody is going to eventually follow the (now-ill-advised) directions, and expect me to take responsibility for their own dumbassery. Apparently that’s the world...

This has been replicated from Project64 at https://project64.c64.org/hw/dolphindos.txt for preservation purposes only. While the content remains largely the same, it has been formatted and corrected for spelling, with additions for clarity only. The following document was written into electrical form by Tony Cavén.All rights reserved remain on the original copyright owner.Writing has been done to preserve the document and as it seems to be...

A cartridge to LOAD cartridges, for the C64!
Not a drive replacement, but a way to keep and launch your single PRGs and CRT files easily. Adds MIDI and COM capability too!

Much as we love our Commodore computers, we all know its video output was... not the best. Back in the day, it didn't matter so much, but today there's a way to make it all better!

A backup archive of another C64 software site (mostly related to interfacing with DOS/Win systems)

Don't have a 1541 floppy drive to play with? Don't want to wear out your drive and floppies? Feeling... frugal?
Get a Pi3 and one of these!

This is my attempt to document and catalog all the (proven) mods and upgrades makers have developed for our beloved system over the years.

Getting my C64 online with a modern (and cheap) wifi solution!

On this page you can find all the gathered information found on the web to fix your Commodore 64.