changes

NES game Emulator in Linux.c and asm codes.

Changes
"""""""
 The following describes the layout of this changelog.

 In releases with contributions from multiple developers:
---
 Version number
  Area of project changed: Description of change [developer]
---
 In releases with contributions from a single developer:
---
 Version number [developer]
  Area of project changed: Description of change
---

 Changes from older releases may not classify changes by area of project.


 Developer abbreviations:
  TRAC          Charles Bilyue'
  DBJH          Daniel Horchner


 0.831
  5A22: Changed emulation-mode interrupts to NOT zero data bank
   register - thanks to Overload for pointing out that the SNES CPU
   does not do this [TRAC]
  Source: Fixed a bug which prevented compilation on some setups,
   including BeOS [DBJH]
  Sound: Added 8-sample delay before key-on completion [TRAC]
  Timing: Fixed up some IRQ setup logic bugs introduced by the
   NMI logic improvements [TRAC]
  Render: Fixed a few bugs where some window settings were not
   affected by reset [TRAC]
 0.83 [TRAC]
  Sound: Fixed a bug in envelope height reading of channels that weren't
   playing; value to be read wasn't being updated, fixes Secret of
   Evermore
  Sound: Improved envelope timing when envelope settings changed for
   playing voices
  Sound: Altered audio code to base timing on samples instead of cycles
  Sound: Added countdown register emulation to envelope and noise
   timing
  5A22: Corrected emulation-mode interrupts to zero data bank register
  Documentation: Corrected Win32 port compilation requirements, other
   minor improvements
  5A22: Corrected emulation-mode behavior of many opcodes
  5A22: Added variable bus speed emulation, and improved overall timing
  5A22: Fixed some bugs in DMA
  5A22: Changed DMA to no longer be able to access internal CPU registers
  5A22: Added open bus emulation to A-bus
  Render: Fixed a serious bug which could have some pointers used by
   offset-change rendering not be initialized
  PPU: Corrected a behavior of the H/V latches; reading register $2137
   (SLHV) does NOT reset which bits will be read next
  Timing: Changed scanline length back to 341 dots after research on the
   hardware gave this number; still stumped about SGB and Shin Megami
   Tensei
  Timing: Improved NMI emulation; now supports delayed NMI,
   as well as re-acknowledgement of NMI
  Timing: Added consumption of clock cycles by general DMA
  Timing: Changed default SPC700 CPU clock to 1.024MHz
  Sound: Changed APU code to build with update-on-RAM-change by default
  ROM loader: Added support for loading ROMs up to 64Mbit (autodetection
   still needs work)
 0.81
  PPU: Greatly simplied VRAM read/write handling and readded VRAM read
   buffering, thanks to anomie for convincing me to give it another
   chance, and Overload for some information which fixed some
   related glitches [TRAC]
  Timing: Implemented partial HDMA timing [TRAC]
  Render: Improved emulation of sprite priority rotation, thanks to
   anomie for research [TRAC]
  5A22: Improved RDIO emulation [TRAC]
  Source: Moved emulation code for registers internal to the main CPU
   ($4xxx) to main CPU source files [TRAC]
  Screenshots: Fixed a bug where screenshots were not properly saved in
   some screen modes [TRAC]
  SPC700: Fixed a serious bug in the handling of some 16-bit reads,
   thanks to Brad Martin for alerting me to the problem [TRAC]
  Render: Added countdown register support to mosaic effect in
   modes 0-6 [TRAC]
  Render: Fixed a tileset lookup bug in mosaic effect in mode 4 on BG1 
   with 16x16 tiles enabled [TRAC]
  Render: Fixed a register corruption bug in mosaic effect in mode 4 on
   BG2 with 16x16 tiles enabled [TRAC]
  SRAM: Fixed a problem where SRAMs smaller than 64kbit would not be
   mirrored on load [TRAC]
  Render: Fixed an off-by-6 bug in mode 7 vertical flip [TRAC]
  Input: Fixed a few bugs related to multiple 'sticks' in
   joystick/joypad code, thanks to Harekiet for reporting [TRAC]
  Render: Added correct limits to some intermediate calculations
   in mode 7; values (BG1HOFS - M7X) and (BG1VOFS - M7Y) actually
   produce 11-bit signed results, with the MSB taken from bit 13, not
   bit 10; fixes Space Colony escape in Super Metroid; thanks to
   Qwertie's Mode 7 Test which aided immensely in research [TRAC]
  SPC700: Implemented correct RAM initialization pattern (fill each
   byte with bit 5 of its address); thanks to Overload for research,
   and MKendora for informing me of the findings [TRAC]
  DMA: Corrected behavior of HDMA mode 5, thanks to anomie for the
   information [TRAC]
  Render: Added support for the undocumented OBJ size settings,
   thanks to Charles MacDonald and anomie for research [TRAC]
  Timing: Changed scanline length to 335 dots and adjusted frame timers
   to compensate, to match the 61.17Hz NTSC SGB framerate; fixes demon
   fusion in Shin Megami Tensei [TRAC]
  5A22: Improved open bus behavior in several registers [TRAC]
  Source: Eliminated need for building with a patched NASM on Win32
   port, thanks to Nach for getting me to write the object patcher
   [TRAC]
  Source: Fixed object tree autogeneration [TRAC]
  Logo: Another completely new logo! [Siloh]
 0.80
  Misc: Fixed a flaw where divide result registers were not changed
   by division-by-zero [TRAC]
  Input: Fixed a flaw in JOYC1 which caused SMB in Mario All-Stars to
   not acknowledge the start button [TRAC]
  Source: Seperated the makefile for the multiple ports [TRAC]
  Documentation: Cleaned up and clarified the history, and moved it
   to another file [TRAC]
  Ports: Added Linux/Unix build support [DBJH]
  Source: Contributed to the removal of some non-portable code and
   more source clean-up [DBJH]
  ROM loader: Reduced some problems with loading ROMs in non-absolute
   paths [DBJH]
  Ports: Added BeOS build support [DBJH]
  Configuration: Improved the portability of code which handled
   configuration file regeneration [DBJH]
  Source: Fixed a few problems in variable declarations [DBJH]
  GUI: Made ".." come first in the file list [DBJH]
  GUI: Fixed some problems where text would be displayed outside a
   window [DBJH]
  Source: Reorganized the source tree [TRAC]
  65c816: Fixed a serious design flaw in ADC/SBC emulation which caused
   the overflow flag to be set to an unexpected state [TRAC]
  Sound: Removed some extraneous and problematic compile-time directives
   [TRAC]
  Sound: Added clipping and saturation to gaussian interpolation filter,
   thanks to Jonathan Gevaryahu (Lord_Nightmare) and Brad Martin for the
   fixes [TRAC]
  Timing: Moved display period to the start of scanlines [TRAC]
  DMA: Fixed a bug where the B-bus address could not be changed to a value
   equal to the DMA parameter for the same channel [TRAC]
  Timing: Corrected normal display to 224 lines [TRAC]
  Timing: Added support for latching 213C/213D counter registers via
   register 4201 [TRAC]
  Misc: Added support for reading .zip and .gz files [DBJH]
  Render: Fixed a bug where dual-window AND logic would result in
   an entire line being clipped if either window covered the
   whole display [TRAC]
  GUI: Cleaned up some usage of constants in the source [TRAC]
  GUI: Moved some input-related code out of the GUI source [TRAC]
  Input: Added support for using joysticks/joypads to emulate
   controllers; must be set up in controller configuration in GUI
   similar to keyboard input [TRAC]
  Configuration: Changed format of scancodes for input mappings to
   decimal [TRAC]
  Timing: Improved PPU counter latch accuracy [TRAC]
  Render: Restructured windowing code [TRAC]
  Render: Added preliminary window clipping to mode 7 background [TRAC]
  Render: Improved layering order in mode 7, helps Final Fantasy 6
   world map [TRAC]
  SRAM: Corrected LoROM SRAM address ranges, per a theory shared by
   myself and MKendora [TRAC]
  Memory map: Corrected ROM mirroring [TRAC]
  ROM loader: Reduced some problems with starting the emulator in a path
   other than the one where it is located [TRAC]
  Render: Fixed some mode 7-related problems in Y's III and Illusion of
   Gaia; it appears that the intermediate values (BG1HOFS - M7X) and
   (BG1VOFS - M7Y) produce 10-bit signed results; thanks to SNES'9X
   for help [TRAC]
 0.776 [TRAC]
  Render: Added support for dual window clipping with all logic
   modes of backgrounds in modes 5 and 6
  Render: Added full mosaic effect to modes 5 and 6
  Render: Added support for offset change in mode 6
  Render: Fixed an offset map addressing bug in all offset-change
   renderers
  SPC700: Improved CPU cycle count conversion accuracy in PAL emulation
  Configuration: Removed support for old (pre-0.60) format .cfg files
   to help simplify the code and solve a few bugs
 0.774 [TRAC]
  SRAM: Added support for mirrored SRAM at banks F0 and above in LoROM
   memory map, helps Big Sky Troopers and others, thanks to MKendora
   for the information
  Render: Fixed a screen map addressing bug in 16x16-tile background with
   mosaic renderer
  Render: Fixed a pixel count computation bug in 16x16-tile background with
   mosaic renderer
  Render: Fixed a screen map addressing bug in 16x16-tile background with
   offset-change and mosaic renderer
  Render: Added support for dual window clipping with all logic
   modes of 8x8-tile backgrounds with offset change and mosaic in
   modes 2 and 4
  Render: Added support for dual window clipping with all logic
   modes of 16x16-tile backgrounds with offset change and mosaic in
   modes 2 and 4
  Interface: Changed filename prefix for screenshots
  SPC700: Fixed a flaw in SPC700 timers that could cause fractional ticks
   to be lost on timer startup
  SPC700: Fixed a bug which caused the POP PSW opcode to not restore the
   negative flag properly, thanks to Brad Martin for help with this
 0.77 [TRAC]
  SPC700: Fixed the SPC700 timer bug that was supposed to be fixed in
   0.75; not certain how it didn't make it into the release
  Sound: Fixed a serious bug which caused the sound to never be updated
   on DSP register changes; allows the correct attack 15 timing to
   work with FF4, thanks to MKendora and Brad Martin for getting me
   to go back to it
  Sound: Changed behavior of key on and key off registers, should
   be more accurate
  Render: Added support for dual window clipping with all logic
   modes of 8x8-tile backgrounds with offset change and no mosaic in
   modes 2 and 4
  Render: Added support for dual window clipping with all logic
   modes of 16x16-tile backgrounds with offset change and no mosaic in
   modes 2 and 4
  65c816: Fixed a bug in which caused the timing position of an IRQ on
   a new scanline to be incorrectly computed; fixes a problem in
   Tetris Attack
 0.751 [TRAC]
  Render: Disabled some debugging code that caused mosaic to be forced
   on in background rendering, thanks to Andr俿 Tangir for pointing
   this out!
 0.75 [TRAC]
  65c816: Corrected address wrapping in direct and stack addressing
   modes, thanks to MKendora for pointing out these problems
  65c816: Altered register allocation
  SPC700: Altered register allocation
  SPC700: Fixed a bug in the timers which caused them to be reset
   to random values when turned on, thanks to Brad Martin for pointing
   this out
  Source: Removed some obsolete code and dependencies
  Source: Started cleaning up many of the C label references in the asm
   code
  Render: Added support for dual window clipping with XOR or XNOR logic
   modes of 8x8-tile backgrounds with no offset change or mosaic
  Render: Fixed a bug where window clipping was not updated correctly
   when changing layering order
  Render: Added support for dual window clipping with all logic
   modes of 16x16-tile backgrounds with no offset change or mosaic in
   modes 0-4
  Render: Added support for dual window clipping with all logic
   modes of 8x8-tile backgrounds with mosaic and no offset change
  Render: Added support for dual window clipping with all logic
   modes of 16x16-tile backgrounds with mosaic and no offset change in
   modes 0-4
 0.74 [TRAC]
  Render: Altered clip window setup code
  Sound: Corrected behavior of invalid range values in BRR header byte,