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The Commodore 64 Emulator with the extra dimension

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Commodore 64

You can select the debugger from the console with F6.

Disassembler and debugger

The Debugger has three section, change the section with the TAB key:


The disassembly shows the memory content as CPU instructions. You can navigate with the cursor keys as follows:

Up Move to previous instruction
Down Move to next instruction
Right Follow branch or jump destination
Left Move to current (PC) instruction
Page Up Scroll a page of instructions up
Page Down Scroll a page of instructions down

The following keys controls the execution:
Return Step next instruction in pause mode
Space Toggle Run/Pause
B Toggle a breakpoint at the select instruction
I Toggle an infopoint at the select instruction

A breakpoint stops program execution when the PC is set to the address.
An infopoint writes a info message to the trace output.
There are much more options for breakpoints an infopoint like conditions. These can be set in the console.


The memory sections shows the current content of the memory from the current view of the CPU.
Use the cursor and page up/down keys to navigate to a specific address. Values are marked green, when they are changed.


The menu lets you control the execution state, change memory, registers and much more.

The debugger will automatically disassemble, when the emulator is pause.
Within the debugger breakpoints can be set and cleared. The CPU registers and flags are updated on every pause, single step or reaching a breakpoint. Changed values are marked green.

With breakpoints you can trigger and automate actions like changing log levels, creating screenshots and much more.