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11 KiB

izapple2 - Apple ][+, //e emulator

Portable emulator of an Apple II+ or //e. Written in Go.


  • 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
  • Storage

    • 16 Sector 5 1/4 diskettes. Uncompressed or compressed witth gzip or zip. Supported formats:
    • 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)
  • 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)

Running the emulator

No installation required. Download the single file executable izapple2xxx_xxx for linux or Mac, SDL2 graphics or console. Build from source to get the latest features.

Default mode

Execute without parameters to have an emulated Apple //e Enhanced with 128kb booting DOS 3.3 ready to run Applesoft:

casa@servidor:~$ ./izapple2sdl

DOS 3.3 started

Play games

Download a DSK or WOZ file or use an URL (Asimov is an excellent source):

casa@servidor:~$ ./izapple2sdl " (includes intro).dsk"


Play the Total Replay collection

Download the excellent Total Replay compilation by a2-4am:

casa@servidor:~$ ./izapple2sdl Total\ Replay\ v4.0.hdv

Displays super hi-res box art as seen with the VidHD card.

Total Replay

Terminal mode

To run text mode right on the terminal without the SDL2 dependency, use izapple2console. It runs on the console using ANSI escape codes. Input is sent to the emulated Apple II one line at a time:

casa@servidor:~$ ./izapple2console -model 2plus

#                                          #
#                APPLE II                  #
#                                          #
#     DOS VERSION 3.3  SYSTEM MASTER       #
#                                          #
#                                          #
#            JANUARY 1, 1983               #
#                                          #
#                                          #
#                                          #
#                                          #
# ]10 PRINT "HELLO WORLD"                  #
#                                          #
# ]LIST                                    #
#                                          #
# 10  PRINT "HELLO WORLD"                  #
#                                          #
# ]RUN                                     #
# HELLO WORLD                              #
#                                          #
# ]_                                       #
#                                          #
#                                          #


  • Ctrl-F1: Reset button
  • F5: Toggle speed between real and fastest
  • Ctrl-F5: Show current speed in Mhz
  • F6: Toggle between NTSC color TV and green phosphor monochrome monitor
  • F7: Show the video mode and a split screen with the views for NTSC color TV, page 1, page 2 and extra info.
  • F10: Cycle character generator code pages. Only if the character generator ROM has more than one 2Kb page.
  • Ctrl-F10: Show the charater map for the current character generator page.
  • Shift-F10: When showing the character map, use altText.
  • F11: Toggle on and off the trace to console of the CPU execution
  • F12: Save a screen snapshot to a file snapshot.png
  • Pause: Pause the emulation

Only valid on SDL mode

Command line options

  -charRom string
        rom file for the character generator (default "<default>")
  -consoleCardSlot int
    	  slot for the host console card. -1 for none (default -1)
  -disk string
        file to load on the first disk drive (default "<internal>/dos33.dsk")
  -disk2Slot int
        slot for the disk driver. -1 for none. (default 6)
  -disk35 string
        file to load on the SmartPort disk (slot 5)
  -diskRom string
        rom file for the disk drive controller (default "<internal>/DISK2.rom")
  -diskb string
        file to load on the second disk drive
  -fastChipSlot int
        slot for the FASTChip accelerator card, -1 for none (default 3)
        force all letters to be uppercased (no need for caps lock!)
        set fast mode when the disks are spinning (default true)
  -hd string
        file to load on the boot hard disk
  -hdSlot int
        slot for the hard drive if present. -1 for none. (default -1)
  -languageCardSlot int
        slot for the 16kb language card. -1 for none
  -memoryExpSlot int
        slot for the Memory Expansion card with 1GB. -1 for none (default -1)
  -mhz float
        cpu speed in Mhz, use 0 for full speed. Use F5 to toggle. (default 1.0227142857142857)
  -model string
        set base model. Models available 2plus, 2e, 2enh, base64a (default "2enh")
  -mouseCardSlot int
    	  slot for the Mouse card. -1 for none (default 4)
  -nsc int
        add a DS1216 No-Slot-Clock on the main ROM (use 0) or a slot ROM. -1 for none (default -1)
        panic if a not implemented softswitch is used
  -printer int
        slot for the Parallel Printer Interface. -1 for none (default 1)
        generate profile trace to analyse with pprof
  -ramworks int
        memory to use with RAMWorks card, 0 for no card, max is 16384 (default 8192)
        emulate the RGB modes of the 80col RGB card for DHGR (default true)
  -rom string
        main rom file (default "<default>")
        emulate a RomX
  -saturnCardSlot int
        slot for the 256kb Saturn card. -1 for none (default -1)
        use the sequencer based Disk II card
        activate a Swyft Card in slot 3. Load the tutorial disk if none provided
  -thunderClockCardSlot int
        slot for the ThunderClock Plus card. -1 for none (default 4)
        trace BBC MOS API calls used with Applecorn, skip console I/O calls
        trace BBC MOS API calls used with Applecorn
        dump to the console the CPU execution. Use F11 to toggle.
        dump to the console the hd/smartPort commands
        dump to the console the calls to ProDOS machine language interface calls to $BF00
        dump to the console the calls to the Apple Pascal BIOS
        dump to the console the sofswitches calls
        dump to the console the sofswitch registrations
  -vidHDSlot int
        slot for the VidHD card, only for //e models. -1 for none (default 2)
  -videxCardSlot int
    	  slot for the Videx Videoterm 80 columns card. For pre-2e models. -1 for none (default 3)

Building from source


Besides having a working Go installation, install the SDL2 developer files. Run:

git clone
cd izapple2/frontend/a2sdl
go build .


With a working Go installation, run:

brew install SDL2
git clone
cd izapple2/frontend/a2sdl
go build .


On Windows, CGO needs a gcc compiler. Install mingw-w64 and the SDL2 developer files for mingw-64.


git clone
cd izapple2\frontend\a2sdl
go build .

To run in Windows, copy the file SDL2.dll on the same folder as a2sdl.exe. The latest SDL2.dll can be found in the Runtime binary for Windows 64-bit.

Use docker to cross compile for Linux and Windows

To create executables for Linux and Windows without installing Go, SDL2 or the Windows cross compilation toosl, run:

cd docker