izapple2 v2.5 is released. Portable emulator of an Apple II+ or //e. Written in Go.

Current Features:
Models:
Apple ][+ with 48Kb of base RAM
Apple //e with 128Kb of RAM
Apple //e enhanced with 128Kb of RAM
Base64A clone with 48Kb of base RAM and paged ROM
Basis 108 clone (partial)
Storage
16 Sector 5 1/4 diskettes. Uncompressed or compressed witth gzip or zip. Supported formats:
NIB (read only)
DSK
PO
WOZ 1.0 or 2.0 (read only)
13 Sector 5 1/4 diskettes. Uncompressed or compressed witth gzip or zip. Supported formats:
NIB (read only)
WOZ 2.0 (read only)
3.5 disks in PO or 2MG format
Hard disk in HDV or 2MG format with ProDOS and SmartPort support
Emulated extension cards:
DiskII controller (state machine based for WOZ files)
16Kb Language Card
256Kb Saturn RAM
Parallel Printer Interface card
1Mb Memory Expansion Card (slinky)
RAMWorks style expansion Card (up to 16MB additional) (Apple //e only)
ThunderClock Plus real time clock
Apple //e 80 columns card with 64Kb extra RAM and optional RGB modes
No Slot Clock based on the DS1216
Videx Videoterm 80 column card with the Videx Soft Video Switch (Apple ][+ only)
SwyftCard (Apple //e only)
Brain Board
Brain Board II
MultiROM card
Dan ][ Controller card
ProDOS ROM card
Useful cards not emulating a real card
Bootable SmartPort / ProDOS card with the following smartport devices:
Block device (hard disks)
Fujinet network device (supports only http(s) with GET and JSON)
Fujinet clock (not in Fujinet upstream)
VidHd, limited to the ROM signature and SHR as used by Total Replay, only for //e models with 128Kb
FASTChip, limited to what Total Replay needs to set and clear fast mode
Mouse Card, emulates the entry points, not the softswitches.
Host console card. Maps the host STDIN and STDOUT to PR# and IN#
ROMXe, limited to font switching
Graphic modes:
Text 40 columns
Text 80 columns (Apple //e and Videx VideoTerm)
Low-Resolution graphics
Double-Width Low-Resolution graphics (Apple //e only)
High-Resolution graphics
Double-Width High-Resolution graphics (Apple //e only)
Super High Resolution (VidHD only)
Mixed mode
RGB card text 40 columns with 16 colors for foreground and background (mixable)
RGB card mode 11, mono 560x192
RGB card mode 12, ntsc 160*192
RGB card mode 13, ntsc 140*192 (regular DHGR)
RGB card mode 14, mix of modes 11 and 13 on the fly
Displays:
Green monochrome monitor with half width pixel support
NTSC Color TV (extracting the phase from the mono signal)
RGB for Super High Resolution and RGB card
ANSI Console, avoiding the SDL2 dependency
Debug mode: shows four panels with actual screen, page1, page2 and extra info dependant of the video mode
Tracing capabilities:
CPU execution disassembled
Softswitch reads and writes
ProDOS MLI calls
Apple Pascal BIOS calls
SmartPort commands
BBC MOS calls when using Applecorn
Other features:
Sound
Joystick support. Up to two joysticks or four paddles
Mouse support. No mouse capture needed
Adjustable speed
Fast disk mode to set max speed while using the disks
Single file executable with embedded ROMs and DOS 3.3
Pause (thanks a2geek)
Passes the A2AUDIT 1.06 tests as II+, //e, and //e Enhanced.
Partial pass ot the ProcessorTests for 6502 and 65c02. Failing test 6502/v1/20_55_13; flags N anv V issues with ADC; and missing some undocumented 6502 opcodes.
By default the following configuration is launched:
Enhanced Apple //e with 65c02 processor
RAMWorks card with 80 column, RGB (with Video7 modes) and 8Gb RAM in aux slot
Parallel print inteface in slot 1
VidHD card (SHR support) in slot 2
FASTChip Accelerator card in slot 3
Mouse card in slot 4
SmartPort card with 1 device in slot 5 (if an image is provided with -disk35)
DiskII controller card in slot 6
SmartPort card with 1 device in slot 7 (if an image is provided with -hd)Models:
Apple ][+ with 48Kb of base RAM
Apple //e with 128Kb of RAM
Apple //e enhanced with 128Kb of RAM
Base64A clone with 48Kb of base RAM and paged ROM
Basis 108 clone (partial)
Storage
16 Sector 5 1/4 diskettes. Uncompressed or compressed witth gzip or zip. Supported formats:
NIB (read only)
DSK
PO
WOZ 1.0 or 2.0 (read only)
13 Sector 5 1/4 diskettes. Uncompressed or compressed witth gzip or zip. Supported formats:
NIB (read only)
WOZ 2.0 (read only)
3.5 disks in PO or 2MG format
Hard disk in HDV or 2MG format with ProDOS and SmartPort support
Emulated extension cards:
DiskII controller (state machine based for WOZ files)
16Kb Language Card
256Kb Saturn RAM
Parallel Printer Interface card
1Mb Memory Expansion Card (slinky)
RAMWorks style expansion Card (up to 16MB additional) (Apple //e only)
ThunderClock Plus real time clock
Apple //e 80 columns card with 64Kb extra RAM and optional RGB modes
No Slot Clock based on the DS1216
Videx Videoterm 80 column card with the Videx Soft Video Switch (Apple ][+ only)
SwyftCard (Apple //e only)
Brain Board
Brain Board II
MultiROM card
Dan ][ Controller card
ProDOS ROM card
Useful cards not emulating a real card
Bootable SmartPort / ProDOS card with the following smartport devices:
Block device (hard disks)
Fujinet network device (supports only http(s) with GET and JSON)
Fujinet clock (not in Fujinet upstream)
VidHd, limited to the ROM signature and SHR as used by Total Replay, only for //e models with 128Kb
FASTChip, limited to what Total Replay needs to set and clear fast mode
Mouse Card, emulates the entry points, not the softswitches.
Host console card. Maps the host STDIN and STDOUT to PR# and IN#
ROMXe, limited to font switching
Graphic modes:
Text 40 columns
Text 80 columns (Apple //e and Videx VideoTerm)
Low-Resolution graphics
Double-Width Low-Resolution graphics (Apple //e only)
High-Resolution graphics
Double-Width High-Resolution graphics (Apple //e only)
Super High Resolution (VidHD only)
Mixed mode
RGB card text 40 columns with 16 colors for foreground and background (mixable)
RGB card mode 11, mono 560x192
RGB card mode 12, ntsc 160*192
RGB card mode 13, ntsc 140*192 (regular DHGR)
RGB card mode 14, mix of modes 11 and 13 on the fly
Displays:
Green monochrome monitor with half width pixel support
NTSC Color TV (extracting the phase from the mono signal)
RGB for Super High Resolution and RGB card
ANSI Console, avoiding the SDL2 dependency
Debug mode: shows four panels with actual screen, page1, page2 and extra info dependant of the video mode
Tracing capabilities:
CPU execution disassembled
Softswitch reads and writes
ProDOS MLI calls
Apple Pascal BIOS calls
SmartPort commands
BBC MOS calls when using Applecorn
Other features:
Sound
Joystick support. Up to two joysticks or four paddles
Mouse support. No mouse capture needed
Adjustable speed
Fast disk mode to set max speed while using the disks
Single file executable with embedded ROMs and DOS 3.3
Pause (thanks a2geek)
Passes the A2AUDIT 1.06 tests as II+, //e, and //e Enhanced.
Partial pass ot the ProcessorTests for 6502 and 65c02. Failing test 6502/v1/20_55_13; flags N anv V issues with ADC; and missing some undocumented 6502 opcodes.
By default the following configuration is launched:
Enhanced Apple //e with 65c02 processor
RAMWorks card with 80 column, RGB (with Video7 modes) and 8Gb RAM in aux slot
Parallel print inteface in slot 1
VidHD card (SHR support) in slot 2
FASTChip Accelerator card in slot 3
Mouse card in slot 4
SmartPort card with 1 device in slot 5 (if an image is provided with -disk35)
DiskII controller card in slot 6
SmartPort card with 1 device in slot 7 (if an image is provided with -hd)

izapple2 Changelog:
Highlights
Disk images are kept unmodified with a save directory. With -saveDir, what the software writes goes to an overlay file there and the image is only read. Overlays store only the tracks or blocks written and are tied to a checksum of their image. This also makes writable the disks that could not be written before: inside a zip or gzip, loaded from a URL, or embedded in the executable.
DOS 3.3 boots in five seconds. The Disk II motor keeps turning for about a second after the drive is turned off, like the 556 timer of the real controller, and the data latch no longer reads the same nibble twice. DOS no longer waits for the motor on every access: a DOS 3.3 boot takes 5.4 million cycles instead of 36 million.
A libretro core runs izapple2 inside RetroArch and the other libretro frontends, with diskette swapping from M3U playlists and saves as overlays. It is built from source and is not in the release archives. See the libretro page and the Mac guide.
An experimental SDL3 frontend, a2sdl3, which builds with nothing installed but Go: no cgo, no C compiler, no SDL developer files. It is not in the release archives, which stay on SDL2.
Emulation
Offete Forth ROM card (forthrom), and a new forth model: an Apple ][+ with Forth in ROM.
New gaming model: an enhanced //e with a Mockingboard, a FastChip and no mouse or VidHD. It is the default of the libretro core.
Four screen modes, from two independent choices: green or color, with or without the gaps between the scan lines.
Hard disk images inside a zip file are found. Before, only diskettes were looked for.
Command line
-saveDir to keep the disk images unmodified, with a savedir parameter on the cards that write to their disks.
-screen sets the screen mode to start with: color, colorscanlines, green or greenscanlines.
-board sets the main board: 2plus, 2e, base64a or basis108.
-model none starts with no model, taking the board and the ROMs from -board, -rom and -charrom.
Frontends
F8 shows the drives a file can be dropped on, each with the image it has inserted. The same screen appears briefly after a drop, with the drive that got the file marked. Machines with two Disk II cards can reach all four drives.
Ebiten frontend: mouse support, and drag and drop of disk images, which the help claimed but did not exist.
The frontends share their keyboard, joystick, mouse, sound and help code, so they behave the same:
Ctrl with a letter works on the Ebiten and WASM frontends.
The apple keys are found by their position, so they work on the keyboard layouts where Alt produces another symbol (#44), and they are released when the window loses focus.
SDL2 frontend: a dropped file goes to the drive under the pointer even when the motion events did not arrive during the drag.
A program that drives the machine with RunCycles can read the screen text and the memory, and load a disk: ScreenText, Peek, GetPC and LoadDisk.
Fixes
Formatting a blank diskette with INIT no longer hangs the emulator when the address field of a track wraps around the end of the track.
The text of a Videx card is read only while it is the screen being shown.
No file descriptor is leaked on every track written to a diskette.
Documentation
A page per frontend with how to build it, how to use it and what it does not do, and the feature list in doc/features.md.
The documented default configuration is now generated from -showConfig. It listed cards and flags that the default machine no longer has.
Pull requests
A libretro core, and the pieces it needed by @ivanizag in #42
Experimental SDL3 frontend by @ivanizag in #40
Find the apple keys by scancode on SDL3 by @ivanizag in #46
Bump postcss from 8.5.20 to 8.5.26 in /frontend/a2wasm in the npm_and_yarn group across 1 directory by @dependabot[bot] in #47
A page per frontend by @ivanizag in #48
Show the drives a file can be dropped on by @ivanizag in #49
Share the frontend code that does not depend on the toolkit by @ivanizag in #50
Bump the npm_and_yarn group across 1 directory with 2 updates by @dependabot[bot] in #51

Download: izapple2 v2.5
Source:Here