bashouston.blogg.se - 6502 emulator source code

#6502 EMULATOR SOURCE CODE UPDATE#
#6502 EMULATOR SOURCE CODE FULL#
#6502 EMULATOR SOURCE CODE CODE#
#6502 EMULATOR SOURCE CODE PC#
#6502 EMULATOR SOURCE CODE SERIES#

(Mind that you can temporarily disable/enable ROM by calling " cpu6502.enableROM()" from the browser's JavaScript console.) Illegal Opcodes Officially, the instruction was not yet implemented.) (With this infamous bug of the early 6502 production series, the ROR instruction behaves like ASL, but shifts in zero and preserves the carry flag.

#6502 EMULATOR SOURCE CODE SERIES#

The option "emulate pre-June 1976 series ROR bug" found below the KIM-1 ROM entry may be also used without this ROM. Note: the KIM-1 (© CBM) consits only of the main ROM and doesen't comprise the cassette extension. However, you can still write to the underlaying Quot shadow" RAM. ROMs will be loaded in a write-protected area of their own.

Loading ROMsįor those who can't help nostalgia, there are a few ROM sets ready to load. You may specify a byte value to be used as a fill byte (e.g., " EA", NOP, as used by the C64) in the confirmation prompt. Use the button "clear meory" to reset the memory. Alternatively, the button "Look Up Mem #" (found among the emulator controls at the top) provides a dialog for a quick inspection of a 16-byte range around any memory address.The option "ignore ROM" bypasses any loaded ROMs and shows RAM content only.

#6502 EMULATOR SOURCE CODE UPDATE#

The option "live update" causes the memory display to update with each step of the emulator.

(Any figures prefixed or suffixed by a colon (" :") are ignored as line numbers.) You may alter the display's content and load it back into the emulator's memory.

The memory widget lets you also inspect the memory, in steps of 256 (0x100) bytes (a page of memory) at once.

Specify the start address (in hex) and press the button "Load Memory".

Or use the file upload button located immediately below the memory pane. Or drag & drop a binary file or hex-dump file onto the memory pane,

#6502 EMULATOR SOURCE CODE CODE#

Enter (and edit) any amount of hex code in the memory inspector's pane,.

The 6502's stack of 1K range is located at 0100 to 01FF (hard wired).

#6502 EMULATOR SOURCE CODE FULL#

The emulator implements 64K of memory for the full 16-bit address range. Interrupts (on execution of a BRK instruction, code 00) will always trigger a trap. These observers may by activated/deactivated both individually and globally.

Traps may observe the value of any of the 3 main registers (AC, XR, YR), watch for an under- or overflow of the stack register (SR), or monitor for the program counter (PC) by setting a breakpoints. You may set any number of traps or breakpoints, which will be monitored in continuous run mode.

Click a registers label to set its value.

The cycle time display shows the clock ticks of exceeded CPU time (including extra cycles for branches and page transitions). The line disassembler shows the current value of the program counter (PC), the content of the according memory address (the next instruction followed by the operands, if any), and a disassembly of the respective instruction. The status register (SR) holds the following flags (from bit 7 to 0): N

#6502 EMULATOR SOURCE CODE PC#

This display shows all (yes its all there is) registers of a 6502/6510 CPU: PC Observe the tool-tips of any options for further information or read the description below. Using the file upload button or drag-and-drop, files may be text files containg a similar hex dump or binary files. Any heading line numbers or addresses preceded or followed by a colon (" :") are ignored, as are any comments (starting with a semicolon or a backslash). The object code may be a series of byte values in hex format (in pairs of two or separated by white space and/or commas).

Press "Show Memory" to display a page of memory starting at the currently specified start address.Ĭlick the option "live update" to observe any changes to the memory in real-time.

Optionally click the checbox "trace" for a detailed log of operations.

Click the buttons "Single Step" or "Continuous Run".

At the processor display, set the program counter by either clicking the location display or its title.

Enter a start address (hexadecimal) and press "Load Memory".

This memory be a series of hex values or a binary file.

Paste, drag-and-drop, or upload (using the file dialog button) the object code into the code field.

Select your preferred color scheme by clicking the options "Dark" and "Light" at the top right.

Addr instr disass | AC XR YR SP| nvdizc| # Clear