32 lines
1.7 KiB
Markdown
32 lines
1.7 KiB
Markdown
# PC Speaker
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40 years of one square beep – and still going! Single channel, no volume control...
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# real output
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so far this is the only chip in Furnace which has a real hardware output option.
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to enable it, select file > configure chip... > PC Speaker > Use system beeper.
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be noted that this will only work on Linux as Windows does not provide any user-space APIs to address the PC speaker directly!
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you may configure the output method by going in Settings > Emulation > PC Speaker strategy:
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- `evdev SND_TONE`: uses input events to control the beeper.
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- requires write permission to `/dev/input/by-path/platform-pcspkr-event-spkr`.
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- is not 100% frequency-accurate as `SND_TONE` demands frequencies, but Furnace uses raw timer periods...
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- `KIOCSOUND on /dev/tty1`: sends the `KIOCSOUND` ioctl to control the beeper.
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- may require running Furnace as root.
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- `/dev/port`: writes to `/dev/port` to control the beeper.
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- requires read/write permission to `/dev/port`.
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- `KIOCSOUND on standard output`: sends the `KIOCSOUND` ioctl to control the beeper.
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- requires running Furnace on a TTY.
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- `outb()`: uses the low-level kernel port API to control the beeper.
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- requires running Furnace as root, or granting it `CAP_SYS_RAWIO` to the Furnace executable: `sudo setcap cap_sys_rawio=ep ./furnace`.
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real hardware output only works on BIOS/UEFI (non-Mac) x86-based machines! attempting to do this under any other device **will not work**, or may even brick the device (if using `/dev/port` or `outb()`)!
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oh, and of course you also need the beeper to be present in your machine. some laptops connect the beeper output to the built-in speakers (or the audio output jack), and some other don't do this at all.
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# effects
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ha! effects...
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