AppleWin/source/frontends/sdl

SA2: Apple ][ Emulator for Linux based on SDL2

This file only lists options not already described in -h.

Configuration

There is no GUI to configure the emulator: either manually edit the configuration file ~/.applewin/applewin.conf or use qapple and run sa2 --qt-ini. The format of the configuration file is the same as the Windows Registry of AppleWin.

Individual options can be passed via arguments too: -c Configuration.Printer_FileName=Printer.txt.

If you have a modern gamepad where the axes (LEFTX and LEFTY) move in a circle, the emulator will automatically map to a square: use --no-squaring to avoid this.

Raspberry Pi

On a Raspberry Pi, one needs the KMS (fake or not). Better performance has been observed with the opengles2 driver (use sa2 --sdl-driver 1).

It is possible to run the CPU in a separate thread to keep the emulator running in real time (necessary for slower Pis, with some Apple video types and bigger window sizes):

• sa2 -m
• optionally add -l

Dear ImGui

With the flag --imgui, the rendering if performned with Dear ImGui. In this case --sdl-driver is ignored and a OpenGL ES2.0 implementation is required.

On a Raspberry Pi, a KMS driver is mandatory and best results are obtained on a Pi4 with FullKMS (full screen via F6).

Output mentions the Dear ImGui version, e.g.: IMGUI_VERSION: 1.81 WIP.

Hotkeys

F2, F5, F6, F9, F11, F12 and Pause have the same meaning as in AppleWin.

Left Alt and Right Alt emulate the Open and Solid Apple key.

Audio

Audio works reasonably well, using AppleWin adaptive algorithm.

Use F1 during emulation to have an idea of the size of the audio queue

Channels: 1, buffer: 32768, SDL:  8804, queue: 0.47 s
Channels: 2, buffer: 45000, SDL: 65536, queue: 0.63 s

(1) is the speaker, (2) the Mockingboard.

Speech / phonemes are known to hang the emulator.

Speed diagnostic

At the end of the run, it will print stats about timings:

Video refresh rate: 60 Hz, 16.67 ms
Global:  [. .], total =    7789.16 ms, mean =    7789.16 ms, std =       0.00 ms, n =      1
Events:  [0 M], total =      22.42 ms, mean =       0.05 ms, std =       0.17 ms, n =    471
Texture: [0 M], total =     113.32 ms, mean =       0.24 ms, std =       0.06 ms, n =    471
Screen:  [0 .], total =    7624.87 ms, mean =      16.19 ms, std =       1.66 ms, n =    471
CPU:     [1 M], total =     647.21 ms, mean =       1.34 ms, std =       0.48 ms, n =    484
Expected clock: 1020484.45 Hz, 7.74 s
Actual clock:   1014560.11 Hz, 7.79 s

The meaning of [0 M] is: 0/1 which thread and M if it is in the mutex protected area.

• events: SDL events and audio
• texture: SDL_UpdateTexture
• screen: SDL_RenderCopyEx and SDL_RenderPresent (this includes vsync)
• cpu: AW's code

They do not include time spent in locking.

The clock shows expected vs actual speed.