JPL64 Commodore 64 Emulator
---------------------------

by JPL ( James Purcell)
I know there are lots of emulators for the 64 but I wanted
to see if my knowledge of the 64 was enough for me write one.

so here it is.

everything has been written from scratch using just my own knowledge
I have not used any work from any other.

please feel free to try it and give me some feedback.

I welcome comments and improvement suggestions.

this is nowhere near as good as the mighty VICE or Hox64 (but its getting there)

Supported
---------

1531 Mouse
Most Cartridge formats (there are a few issues here)
1541 Emulation
TAP
REU 16mb
DigiMax
Dual SID , [6581 @ d400] & [8580 @ d420 & d500] 
SFX-Sound Expander

The Joysticks are mapped as follows

Numeric keypad
1235 & 0 joystick 2
789/ & 4 joystick 1

F9  - Debug toggle C64 / 1541

F10 - Debugger on/off
in debugger use cursor down key to single step a cycle.
the debugger is WIP and severely lacking currently.

F11 - Full Screen
select a full screen mode from the setup menu
before using this option. select a mode as close to 50hz as possible
I always use 1920 x 1080 @ 50hz


HOME - options menu


Whats new.
----------
v0.07 - REU support has been improved.
      - Broader CRT support
      - SID Emulation improved
	SFX-FM / Sound expander support added
	1541 True drive emulation improvements
	CIA Timer improvements
	Illegal Opcodes ISB & SHA had small flag bug - FIXED
	6510 IRQ handling IRQ/NMI fixes. far better accuracy
	VIC-II fixes around badlines & bus arbitration 

v0.06 - CIA 6526 further improvements to timers
	CPU branch instructions occasionally lost a cycle. fixed
	SID ADSR envelopes almost very nearly cycle accurate
	SID filter changed AGAIN!!!!.. way way better. very nearly perfect to my ears.
	1541 emulation, no more IEC protocol code
		VIA 6522 85% complete.
		uses same cpu core as C64
		BUS emulation getting there.
	
v0.05 - CIA 6526 work ongoing to make this cycle exact. now emulates subtle
	cycle delays for interrupt triggers
	VIC II - fixes for bus arbitration sequence BA & AEC
	SID filter changed again this time to a ladder filter
	fixes up the menus as requested.
	added a clean exit as requested

v0.04 - second sid enabled any music that writes to d420 or d500 will
	use the second sid, sid located at $d400 is 6581 and the second
	is the 8580 (only real difference is the filter profile)
      - completely rewritten sid filters in favour of a fast ZDF core
      - further cartridge support. most carts work now.
        if you find any that don't please let me know.

v0.03 - sid filters, better still some issues but better
      - sid envelopes, full, cycle exact, emulates ADSR bugs & quirks
      - sid waveforms, fixed noise, now using mixed luts rather than logical and of waveforms 
      - sid ring modulation, fixed better
      - debugger works better, press f10 to enter and down arrow to step by cycle
      - cia 1&2 fixes for other timer modes

v0.02 - fixed cia oneshot timers reloading latch
      - fixes for easyflash HIROM banks
      - added fullscreen mode selector
      - fixed a bug in indirect JMP
      - added vic sprite background collision emulation
      - added vic sprite sprite collision detection
      - started to lay ground work for debugger breakpoints

v0.01 - initial release


all criticism, ideas etc are welcome jamespurcell191@yahoo.com

Thanks 

JPL



