goarcade

An arcade game emulator based on the Intel 8080 CPU, written in Golang. It can play classic arcade games like 1978 Space Invaders.

• Passes common 8080 CPU tests
• Timing accurate (CPU @ 2MHz, UI @ 60Hz)
• Performance optimized, uses <10% of a CPU core (tested on a Ryzen 5 2600 CPU) when running at 2MHz
• SDL3 UI without needing CGo at build time using zyko0/go-sdl3
• Compatible with MAME archive games
• Game support configurable without rebuild using config.yaml
• Comprehensive CLI interface
• Audio support (numbered WAV files: 0.wav, 1.wav...)
• Pause, reset, save states

Usage

No game ROM included, do your own research :)

# Download dependencies
> go mod download

# Build emulator
> go build

# Help
> ./goarcade help
NAME:
   goarcade - Intel 8080 arcade emulator

USAGE:
   goarcade [global options] [command [command options]] [rom path (binary file or .zip archive)]

COMMANDS:
   dasm, d  disassemble a program
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --config string, -c string       config file path (default: "./config.yaml")
   --state string, -s string        save state file path
   --sound-dir string, --sd string  directory path for WAV sound files
   --pprof, -p                      run pprof webserver on localhost:6060
   --debug, -d                      print debug logs
   --headless, --hl                 run without UI window
   --mute, -m                       run without audio
   --cpm                            run in CP/M compatibility mode (for CPU tests)
   --unthrottle, -u                 do not throttle cpu at 2MHz
   --help, -h                       show help

# Example: running space-invaders with sound
./goarcade ./roms/invaders/invaders.zip --sd ./roms/invaders/sounds

Controls

• c: add a coin
• 1: 1 player
• 2: 2 players
• left arrow: player left
• right arrow: player right
• left ctrl: player shoot
• p: pause
• r: reset
• 0: save state in game directory (<game_name>.state)
• 9: load state

Test results

Test outputs below are directly generated by a GitHub workflow.

=== RUN   Test_CPU
=== RUN   Test_CPU/TST8080.COM
    main_test.go:28: Output from TST8080.COM:
        MICROCOSM ASSOCIATES 8080/8085 CPU DIAGNOSTIC
         VERSION 1.0  (C) 1980

         CPU IS OPERATIONAL
=== RUN   Test_CPU/8080PRE.COM
    main_test.go:28: Output from 8080PRE.COM:
        8080 Preliminary tests complete
=== RUN   Test_CPU/CPUTEST.COM
    main_test.go:28: Output from CPUTEST.COM:

        DIAGNOSTICS II V1.2 - CPU TEST
        COPYRIGHT (C) 1981 - SUPERSOFT ASSOCIATES

        ABCDEFGHIJKLMNOPQRSTUVWXYZ
        CPU IS 8080/8085
        BEGIN TIMING TEST
        END TIMING TEST
        CPU TESTS OK
=== RUN   Test_CPU/8080EXM.COM
    main_test.go:28: Output from 8080EXM.COM:
        8080 instruction exerciser
        dad <b,d,h,sp>................  PASS! crc is:14474ba6
        aluop nn......................  PASS! crc is:9e922f9e
        aluop <b,c,d,e,h,l,m,a>.......  PASS! crc is:cf762c86
        <daa,cma,stc,cmc>.............  PASS! crc is:bb3f030c
        <inr,dcr> a...................  PASS! crc is:adb6460e
        <inr,dcr> b...................  PASS! crc is:83ed1345
        <inx,dcx> b...................  PASS! crc is:f79287cd
        <inr,dcr> c...................  PASS! crc is:e5f6721b
        <inr,dcr> d...................  PASS! crc is:15b5579a
        <inx,dcx> d...................  PASS! crc is:7f4e2501
        <inr,dcr> e...................  PASS! crc is:cf2ab396
        <inr,dcr> h...................  PASS! crc is:12b2952c
        <inx,dcx> h...................  PASS! crc is:9f2b23c0
        <inr,dcr> l...................  PASS! crc is:ff57d356
        <inr,dcr> m...................  PASS! crc is:92e963bd
        <inx,dcx> sp..................  PASS! crc is:d5702fab
        lhld nnnn.....................  PASS! crc is:a9c3d5cb
        shld nnnn.....................  PASS! crc is:e8864f26
        lxi <b,d,h,sp>,nnnn...........  PASS! crc is:fcf46e12
        ldax <b,d>....................  PASS! crc is:2b821d5f
        mvi <b,c,d,e,h,l,m,a>,nn......  PASS! crc is:eaa72044
        mov <bcdehla>,<bcdehla>.......  PASS! crc is:10b58cee
        sta nnnn / lda nnnn...........  PASS! crc is:ed57af72
        <rlc,rrc,ral,rar>.............  PASS! crc is:e0d89235
        stax <b,d>....................  PASS! crc is:2b0471e9
        Tests complete
--- PASS: Test_CPU
    --- PASS: Test_CPU/TST8080.COM
    --- PASS: Test_CPU/8080PRE.COM
    --- PASS: Test_CPU/CPUTEST.COM
    --- PASS: Test_CPU/8080EXM.COM
PASS

Source for the tests

Profiling

• Use the -p flag to start the profiling webserver

  ./goarcade -p [...]

• In another shell, use go tool pprof to start profiling

  go tool pprof http://localhost:6060/debug/pprof/profile?seconds=30

• Use top, web or png commands in the repl to explore the results

References

• 8080 Datasheet
• Pastraiser's 8080 opcode table
• superzazu/8080 emulator
• Computer Archeology
• emulator101.com (via web.archive.org)