New driver for Brother wordprocessor/typewriter LW-30 #10996
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src/mame/brother/lw30.cpp
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| const lw30_format FLOPPY_LW30_FORMAT; | ||
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| class brother_beep_device : public device_t, public device_sound_interface |
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Is this beeper used by other Brother machines? If it is, it should be moved out to a separate file in mame/brother so it can be shared.
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This custom beeper device doesn't make much sense to me, almost all of it is a copy of sound/beep.*
Looking at the comments below (where it calls beeper_w), isn't the hardware just a 1bit dac?
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Nope, looking further, it's like a dac_2bit_ones_complement_device, where one bit is software controlled and the other is 4khz(can use clock_device for that)
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Unfortunately it's about 5 years since I reverse-engineered this hardware. As I remember, it uses a fixed 4 kHz beeper, but the Tetris game uses CPU-waitloop-controlled PWM to achieve different frequencies to play a melody. That didn't work with the original MAME beep device, so I modified it. Was something about restarting the oscillator or sth like this. Don't know about other Brother machines because I couldn't find any software on them to use it like the LW-30 Tetris.
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@galibert could you please review the floppy format in this pull request? |
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We can worry about the sound device later – it may be possible to implement it some other way (e.g. DAC with volume control input or something). |
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oh just wanted to commit the addressed comments, and just saw you already did the source cleanup. thanks. |
split off of PR#8202