[VCS] Gopher 0.35.0 2/10/2024

Atari 2600 Emulator: Gopher v0.35.0 2/10/2024

Bug Fixes

• Rewinding of ELF binaries caused visual artefacts on screen
• Changes to screen rendering prevented the VideoChess bot from starting
  • Bug introduced in v0.31.0
• Added ELF to list of valid ROM extensions
  • A file with the .elf extension would not be shown by the ROM selector
• Mouse wheel events could crash the emulator
  • This affected MacOS builds on machines where mouse-wheel style scrolling is done with a touch-pad
• Replay button in tracker window could crash the emulator

Changes

• TIA audio sampled every colour clock
  • This fixes problems with ROMs where the channel volume is update more than twice per scanline
• Added option to enable warning for "undefined symbols" when loading ELF ROMs
  • It is possible to compile an ELF binary with undefined symbols. Rather than reject the file when it is loaded, I have chosen to allow the ROM to execute and to continue until the symbol is referenced (which may never happen)
  • The addition of the warning is in addition to this behaviour and gives the developer the option of being notified of symbol errors sooner
• Added CARTRIDGE SETBANK command
  • It wasn't possible previously to set the current bank of a cartridge. I had originally chosen to avoid the problem because of the high variety of ways a mapper might implement banking (if at all)
  • The options to the SETBANK command vary depending on the specific mapper but generally, a mapper will expect a numeric value

    • Segmented mappers can take multiple numeric values. Separate values with a colon

    • In some instances, segments can be mapped to cartridge RAM. add an 'R' after the segment number to indicate the use of RAM. For example, the 3e mapper allows very flexible mapping of RAM

      CARTRIDGE SETBANK 1R:2

    • Some segmented mappers only allow a predefined 'pattern' of segments. In these cases the numeric value to the SETBANK command will be a pattern number. The two mappers affected by this are Supercharger and Wickstead Design

Other Changes

• Added ELF support for REL32 and PREL31 relocation
• Improved DWARF support for typedefs
• Better decision making over whether variables are in global scope
• Prevent possibility of infinite recursion in DWARF builder

Atari 2600 Emulator: Gopher v0.34.0 19/07/2024

• Changes / Bug Fixes

• Specifying a mapper will not add superchip unless asked
• ARM would sometimes loop endlessly on startup
  • caused by ROMs causing execution errors and not being caught
• DPC+ and CDJF always emulate the end-of-custom-program JMP even when immediat mode is enabled
• 6507 more careful with system symbols
  • system symbols no longer appear as operands for immediate instructions
• ARM yields address of most recent instruction rather than the current PC
  • this isn't a problem for 16bit instructions
    - but for 32bit instructions it resulted in confusing feedback in the source window
• Better handling of DWARF data from alternative ELF files

Atari 2600 Emulator: Gopher v0.33.0 6/07/2024

• improvements

• ELF uses less memory
  • High memory usage is a direct consequence of the rewind system
  • ELF memory is only recorded if it the memory block is volatile
  • Recorded memory is compressed (using a very simple RLE algorithm)
• ARMv7_M architecture
  • Marginal performance improvement in cycle counting
• Television can now cause emulation to break into debugger
  • eg. if VSYNC is absent or too short, etc.
  • Toggled via preferences window (television tab)
• FPS overlay in playmode shows VBLANK/VSYNC information
  • Timeline window in debugger shows VSYNC trace
• Debugger shows break condition in toolbar
  • Information shown is currently very rough
• Holding down the STEP buttons in the control window is now faster

• changes / bug fixes

• DPC+ more careful about resetting fraction fetcher counter when setting the fraction fetcher low byte
  • Whether the reset happens depends on the version of the driver being emulated
• Supercharger
  • Rewind fix in 0.32.0 for fastload implementation was incomplete
• Coprocessor Source Window
  • Fixed parsing of comment lines

• Emulator Development

• Fixed profile targets in Makefile
  • Changes made in b48d487 limited the functionality of pprof

Atari 2600 Emulator: Gopher v0.29.1

Atari 2600 Emulator: Gopher v0.29.0

Atari 2600 Emulator: Gopher v0.28.0

Gravitar (Atari, 1983)

Atari 2600 Emulator: Gopher v0.27

Atari 2600 Emulator: Gopher v0.26.2b

• ???

Atari 2600 Emulator: Gopher v0.26.2 Latest

 MovieCart

• Timecode rendered correctly when movie is rewound to beginning/ This also removes visual artefacts visible at the bottom of the movie image
• Controls now match the reference implementation

Atari 2600 Emulator: Gopher v0.26.1

Atari 2600 Emulator: Gopher v0.26.0

Changes from v0.25.0

 MovieCart

•  Added support for new MovieCart format

 TV

•  SECAM support
•  TV rotation. Manual and automatic
•  Only Moviecart makes use of automatic rotation currently

 ELF

•  StrongARM ROMs use the correct color table for the current television

 ARM debugging

•  Corrected DWARF CALLERS
•  ARM disassembly shows function in tooltip

 Other

•  SDL version logged on startup
•  VideoChess bot can now work with levels 2-8 as well as level 1

Atari 2600 Emulator: Gopher v0.26.1

Atari 2600 Emulator: Gopher v0.26.0

Changes from v0.25.0

 MovieCart

•  Added support for new MovieCart format

 TV

•  SECAM support
•  TV rotation. Manual and automatic
•  Only Moviecart makes use of automatic rotation currently

 ELF

•  StrongARM ROMs use the correct color table for the current television

 ARM debugging

•  Corrected DWARF CALLERS
•  ARM disassembly shows function in tooltip

 Other

•  SDL version logged on startup
•  VideoChess bot can now work with levels 2-8 as well as level 1

Commando (1988, Activision)

Changes from v0.24.2

 ARM

•  improved ARM disassembly, particularly for Thumb-2 instructions
•  implementation of FPU and instructions
•  registers window in debugger
•  COPROC STEP command forward by single ARM instruction
  •  useful in conjunction with source window, local/globals window and/or registers window
  •  preparatory work for ARM level quantum control

 ELF

•  "byte streaming" of ROM data - leading to significant performance improvement
•  initialisation sections executed before main() function
•  Notifications
•  notification icon for coprocessor development files
•  transparency setting
•  fixed conditions under which combinations of notifications are shown

 Bug Fixes

•  fixed bad image stutter when refresh rate is inconsistent
•  crash in timeline window when scrubbing past end of rewind history
•  thumbnailing no longer causes the application to hang if the ARM emulation crashes
•  FPS measurement was broken if television was being nudged
•  "fastload" supercharger ROMs (ie. bin files) would crash debugger

 Known Outstanding Bugs

•  rewinding of ELF ROMs when byte streaming is active sometimes produces a  skewed image

Gopher v0.24.2 1/07/2023

Bug Fixes

• fixed debugger crash when loading 8k mnetwork ROMs

Gopher v0.24.1 28/06/2023

Cosmic Ark (1982, Reaction)

Supercharger

• volume threshold for WAV/MP3 automatically determined
  • this improves the loading of WAV files created with makewav or supercharge

Debugger

• more efficient thumbnail generation for timeline window
• cosmetic change to ARM performance window

Gopher v0.24 18/06/2023

• Debugger

• search open windows with CTRL+SHIFT
  • search term is shown in the menu bar
• tooltips can be disabled
  • indicator in menu bar to indicate tooltip availability
  • holding down shift key will bring up any available tooltip
  • setting persists between sessions
• added CALLERS option to DWARF command
• GREP includes bank number if appropriate
• added COMPARISON command
• timeline window improvements
  • more visual - frame guides, icons, etc.
  • removed tooltip on hover - replaced with more informative toolbar
  • thumbnail appears in timeline window
  • comparison point can be changed

• Bug Fixes

• plusrom failing to adopt a child cartridge no longer crashes the emulator
• thumbnail animation in ROM selector would not always update (animate) satisfactorily
  • application refresh frequency now takes into account whether ROM selector is open
• terminal would open if debugger was quit while emulation was running
  • the terminal would still be open when the debugger was restarted

Gopher v0.23.1 06/06/2023

bug fixes

• fixed debugger "TV Screen" rewinding
  • bleed through frame was wrong
  • screen resizes correctly when rewound
• rewind no longer crashes at reset boundaries
  • under certain conditions the program would panic because of missing rewind entries

Gopher v0.23 29/05/2023

Kangaroo (1983, Atari)

Changes from v0.22.0

playmode

• improved rendering stability
  • applies when monitor is similar in refresh rate to emulated TV
• opengl VSYNC "immediate updates" will synchronise with timer
  • this may improve performance on some systems
• improved sharpen shader, removing ugly graphical artefacts
  • artefacts were particularly noticeable in games with flicker kernels

screenshots

• added new composite screenshot mode
  • composite is very good at capturing motion on the screen
  • activated with CTRL-F12
• other screenshot modes renamed to 'single' and 'motion'
  • activated with F12 and SHIFT-F12 respectively

cartridges

• added SCABS bank switching method

ROM select window

• thumbnailer shows a smoother image

plusrom

• fixed issue with rewind "boundaries" being inserted too often
  • reading from the network queue would insert a boundary
  • a boundary is only needed when data is sent to the network

bug fixes

• using right mouse button to capture mouse for paddle input no longer
  interferes with context menus for any open windows

Gopher v0.22 8/05/2023

Changes from v0.21.0

• debugger

• added JITTER halt target
• better magnification window
• better ARM disassembly
  • Thumb-2 disassembly is incomplete but more informative
  • includes snapshot of registers

• playmode

• reduced CPU usage when emulation is paused

• tracker

• replay selection of tracker history
• improved display

• macro system

• basic scripting of emulator input

• bug fixes

• phantom reads could trigger fastloading in CDF cartridges by mistake
• ARM 'immediate mode' switching while running could crash DPC+ and CDF
  cartridges
• CDFJ+ supports any sized cartridge
• corrected adaptive VSYNC. should now work if it's supported by GFX card
• stack pointer working correctly in the debugger

Gopher v0.21 13/02/2023

Changes from v0.20.0

• Performance

• significant performance increase when built with pgo file. the "release" target in the Makefile does this
  • 18% for regular ROMs
  • 13% for a typical ARM ROM
• DPC+ could return formatted errors on calls to Access(). this had a significant performance impact on cartridges that triggered the error

• Display

• new render pipeline
• better scaling
• screenshotting method altered
• improved input latency

• Controllers

• support for stelladaptor
  • joystick and paddle only (driving controller is not yet supported at all)

• Debugger

• magnification of debugging screen

• Setup Database

• TV entry type changed. existing setup database entries will need to be altered

• Database

• entries can be commented out

• DWARF / local variables

• calculation of call frame address is now correct in more (all?) instances

• Bug Fixes

• fixed ARM memory read bug that was most likely to be encountered during DWARF parsing/loading
• WATCH command would halt on a check of an address, even when other conditions (read/write) were not met
• behaviour of STEP BACK in HBLANK area
• behaviour of random pins

Gopher v0.20 12/02/2023

Gopher v0.19.3 5/10/2022

Gopher Attack (1982, U.S Games Corporation)

Gopher v0.19.2 28/08/2022

Harbor Escape (aka River Raid) (1983, Panda) z włączonymi efektami CRT (ale bez najnowszych, źle wyglądają przynajmniej dla mnie:P)

CRT effects

• added bevel and shine option
• both disabled by default

The rounded corners option was added in v0.19.1 but on its own it's not very effective. Applying the bevel and the shine option completes the effect. More control to both these options will be added in the future.

 

Gopher v0.19.1 25/08/2022

Makefile

• Apple Macs with an ARM chip will no longer use freetype font rendering
  when built with the build or release targets
• see issue #19

Display

• changed relationship between the frame rate limiter and monitor
  synchronisation. this may result in a performance improvement on some systems
• uncapped FPS no longer uses input buffer. this resulted in choppy visuals
• fixed visual bug seen when switching from playmode to the debugger when
  one or the other mode had a "maximised" window

TIA

• missile sprites were not plumbed to player correctly after gameplay
  rewinding. this affected missiles that rely on RESMPx for positioning

Rewind

• joystick and gamepad controllers resume from a neutral position after
  gameplay rewind

ARM Developer

• statistics more carefully collated during rewinding to avoid spikes in
  the data

CRT effect

• added rounded corners option

As of this version I will no longer be compressing the linux/amd64 version with UPX

Gopher v0.19.0 30/05/2022

small performance improvements

• uncapped frame rate increase
  • 16% to 18% (6507 only ROMs)
  • 13% to 16% (a typical ARM ROM)

change of WAV implementation

• this affects the loading of Supercharger tapes
• and the recording of audio to disk
• neither should be noticeable changes

Gopher v0.18.0 21/05/2022

ARM Developer

• debugging window added for global variable inspection
• collision detection of ARM stack with program variables
• static areas window improved
  • clearer indication of memory addresses
  • labeling of named variables in memory
• performance window improved
  • raw ARM cycle values in addition to percentile values
  • kernel focus (VBLANK, Visible Screen, Overscan)
  • performance relative to frame
• access of address 0x00 is treated as illegal (probably null dereference)
• visualisation of CDF streams

VCS RAM and Cartridge RAM Window

• indicates labeling of addresses (using ASM symbol file)
• illustration of 6507 stack usage

Peripherals

• choice of attached peripheral can be overriden on startup

TIA bug fixes

• corrected missile reset to player position for double-width player

Savekey/Atarivox

• EEPROM window (savekey data) works correctly for AtariVox

Debugger

• BREAK NONEXE to halt execution on 6507 execution if PC address is not in the Cartridge or RAM areas

Debugger GUI

• better window management in the debugger
• window state (open/close) saved between sessions

Playmode GUI

• non-integer scaling reintroduced - improved scaling method to avoid uneven scanlines
• bugfix (Windows and MacOS)
  • window repainted during window resizing meaning better visual feedback for the user
• audio can be muted (could already be muted in the debugger)
• state of FPS overlay will carried over between sessions
• "active" pause screen readded as an option (in the prefs window)

Gopher 0.17.0 07/04/2022

Changes from v0.16.0

• ARM Developer

• requirement for .obj and .map files replaced with DWARF data
• performance and source windows improved

• ARM

• improved accuracy of T1TC timer
• cycle counting corrected (by one color clock) on CALLFN exit
• clock speed definable

• AtariVox

• added support for AtariVox
• currently only supports Festival for voice synthesis
• missing some AtariVox sounds and effects

• 6507

• all 256 opcodes implemented

• SaveKey

• removed (small) performance bottleneck

• PlusROM

• update network headers to emulate firmware >= v2.1.1

• GUI

• default Dear Imgui font replaced with JetBrainsMono
• font size definable

• Documentation

• Usage documentation now in wiki
  https://github.com/JetSetIlly/Gopher2600-Docs/wiki

Gopher 0.16.0 30/01/2022

H.E.R.O (Activision, Inc., 1984)

ARM

• added support for obj and map files for ARM based ROM projects requires that obj and map file to be created as part of the ROM file's compilation process
• see https://github.com/JetSetIlly/Adventureland-2600 for example of a project setup for this
• added source code, performance and illegal access window. for ROMs where obj and map files are available
• fixed: crash was possible if cart was changed from ARM to non-ARM when
• coprocessor disasm window was open - a race condition with the "lazy data" system

6507

• zero-page indexed addressing causes phantom read correctly this corrects the read values of the TIA registers (collision registers etc) when read with a zero-paged indexed instruction other addressing modes already caused correct phantom reads

RIOT

• port B is now writable from the CPU

Debugger GUI

• ports window replaces chip registers window timer window improved. fixed bug in ticks remaining display and added TIMINT field disassembly window improvements peripherals window replaces controllers window 6507 Pinout window showing the state of the address and data bus on any given color clock

Television

• audio will always play regardless of frame stability
  • an extra condition testing for stability on startup meant that some ROMs never outputted sound if they never reached stability. this rarely matters but it affected the tunabit demo ROM in particular
• added 'Sync On Power' CRT option
  • this will cause the screen to roll on startup

RIOT/Peripherals

• VBLANK latch bit applies only to INPT4 and INPT5
• added support for Genesis controllers
• automatic detection of controllers (using Stella fingerprints)

Cartridge Formats

• added support for EF (with or without superchip)
• cartridges with superchip now respond correctly to phantom memory
• accesses (causing phantom writes in some cases)
• tigervision (3F) now uses the correct method of switching banks
• missing Supercharger BIOS handled gracefully

Bots (WIP)

• added rudimentrary support for bots capable of playing ROMs independently. still a WIP but example bots for spacejockey and video chess have been implemented

ROM Comparisons (WIP)

• two ROMs can now be run in parallel and the output compared and differences highlighted. very specialist use and probably not of much interest

Removals

• linter. existing version was unused and underdeveloped. will reimplement in the future