zsg2: update stream before reading,

tms57002: fix input sample overflow

src/devices/cpu/tms57002/tms57002.cpp

@@ -925,7 +925,7 @@ void tms57002_device::sound_stream_update(sound_stream &stream, std::vector<read
 	assert(inputs[0].samples() == 1);
 	assert(outputs[0].samples() == 1);
 
-	stream_buffer::sample_t in_scale = 32768.0 * ((st0 & ST0_SIM) ? 256.0 : 1.0);
+	stream_buffer::sample_t in_scale = 32767.0 * ((st0 & ST0_SIM) ? 256.0 : 1.0);
 	si[0] = s32(inputs[0].get(0) * in_scale) & 0xffffff;
 	si[1] = s32(inputs[1].get(0) * in_scale) & 0xffffff;
 	si[2] = s32(inputs[2].get(0) * in_scale) & 0xffffff;

src/devices/sound/zsg2.cpp

@@ -1,6 +1,7 @@
 // license:BSD-3-Clause
 // copyright-holders:Olivier Galibert, R. Belmont, hap, superctr
 /*
+
 ZOOM ZSG-2 custom wavetable synthesizer
 
 Written by Olivier Galibert
@@ -85,7 +86,8 @@
 
 TODO:
 - Filter and ramping behavior might not be perfect.
-- clicking / popping noises in gdarius, raystorm: maybe the sample ROMs are bad dumps?
+- clicking / popping noises in gdarius, raystorm: maybe the sample ROMs
+  are bad dumps?
 - memory reads out of range sometimes
 
 */
@@ -639,6 +641,8 @@ uint16_t zsg2_device::read(offs_t offset, uint16_t mem_mask)
 		return 0;
 	}
 
+	m_stream->update();
+
 	if (offset < 0x300)
 	{
 		int chan = offset >> 4;

src/devices/sound/zsg2.h

@@ -58,12 +58,9 @@ private:
 		int16_t output_cutoff_delta;
 
 		int32_t emphasis_filter_state;
-
 		int32_t output_filter_state;
 
-		// Attenuation for output channels
-		uint8_t output_gain[4];
-
+		uint8_t output_gain[4]; // Attenuation for output channels
 		int16_t samples[5]; // +1 history
 	};