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https://github.com/freewilll/apple2-go.git
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8284073beb
Every frame sends a bunch of audio samples in a channel. This channel is consumed by the audio Read() function which is called asynchronously. There's all kinds of timing issues where the audio/video are not aligned. Issues: - There's a large delay between the audio being produced and it being played - Something with the timing is wrong. The first not of lemonade stand and the system beep are both incorrect. Changing the CPU frequency fixes it for one but not for the other. This means something must be wrong in the cycle counting. Also added FPS display that can be toggled with ctrl-alt-F.
45 lines
1006 B
Go
45 lines
1006 B
Go
package system
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const (
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CpuFrequency = 1024000
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AudioSampleRate = 44100
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)
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var (
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PendingInterrupt bool
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PendingNMI bool
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RunningTests bool
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RunningFunctionalTests bool
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RunningInterruptTests bool
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Cycles uint64
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FrameCycles uint64
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AudioCycles uint64
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AudioChannel chan uint16
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LastAudioCycles uint64
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LastAudioValue uint16
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AudioAttenuationCounter uint64
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)
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func Init() {
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Cycles = 0
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AudioChannel = make(chan uint16, AudioSampleRate*4) // 1 second
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LastAudioValue = 0x2000
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}
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// Handle a write to a magic test address that triggers an interrupt and/or an NMI
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func WriteInterruptTestOpenCollector(address uint16, oldValue uint8, value uint8) {
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oldInterrupt := (oldValue & 0x1) == 0x1
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oldNMI := (oldValue & 0x2) == 0x2
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interrupt := (value & 0x1) == 0x1
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NMI := (value & 0x2) == 0x2
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if oldInterrupt != interrupt {
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PendingInterrupt = interrupt
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}
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if oldNMI != NMI {
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PendingNMI = NMI
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}
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}
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