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alesis/midiverb.cpp: Adding the MIDIFEX and its layout. #14174

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alesis/midiverb.cpp: Adding the MIDIFEX and its layout. #14174

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6d0e382
alesis/midiverb.cpp: Adding the MIDIFEX and its layout.
m1macrophage Sep 14, 2025
d822f03
alesis_midifex.lay: Removed stray TODO.
m1macrophage Sep 20, 2025
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23 changes: 22 additions & 1 deletion src/mame/alesis/midiverb.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,10 @@
/*
The MIDIverb is a digital delay & reverb unit.

The MIDIFEX is a digital effects unit, primarily implementing echoes. The
MIDIFEX is just a MIDIverb with a different DSP ROM, and different labeling on
the case. The rest of the hardware and the MCU firmware are the same.

The computer portion of the device is very simple. The firmware runs on a
80C31 microcontroller. It reads the 4 buttons, drives the two 7-segment
displays, and listens to MIDI for program changes. It also controls which
Expand Down Expand Up @@ -56,6 +60,7 @@ Audio inputs are emulated using MAME's audio input capabilities.
#include "video/pwm.h"
#include "speaker.h"

#include "alesis_midifex.lh"
#include "alesis_midiverb.lh"

#define LOG_PROGRAM_CHANGE (1U << 1)
Expand Down Expand Up @@ -259,7 +264,7 @@ u16 midiverb_dsp_device::analog_to_digital(float sample) const
const float transformed = std::clamp(sample, -DAC_MAX_V, DAC_MAX_V) / DAC_MAX_V;

// Quantize to 12 bits, keeping in mind that the range is -1 - 1 (reason
// for "/ 2"). Then convert to 13 bits ("* 2"). Bit 0 is always set ("+ 1).
// for "/ 2"). Then convert to 13 bits ("* 2"). Bit 0 is always set ("+ 1").
const s16 quantized = floorf(transformed * ((1 << 12) / 2 - 1)) * 2 + 1;
assert(quantized > -4096 && quantized < 4096);

Expand Down Expand Up @@ -299,6 +304,7 @@ class midiverb_state : public driver_device
}

void midiverb(machine_config &config) ATTR_COLD;
void midifex(machine_config &config) ATTR_COLD;

DECLARE_INPUT_CHANGED_MEMBER(mix_changed);

Expand Down Expand Up @@ -556,6 +562,12 @@ void midiverb_state::midiverb(machine_config &config)
configure_audio(config);
}

void midiverb_state::midifex(machine_config &config)
{
midiverb(config);
config.set_default_layout(layout_alesis_midifex);
}

DECLARE_INPUT_CHANGED_MEMBER(midiverb_state::mix_changed)
{
update_mix();
Expand Down Expand Up @@ -584,6 +596,15 @@ ROM_START(midiverb)
// "MVOBJ 2-6-86" label.
ROM_END

ROM_START(midifex)
ROM_REGION(0x2000, MAINCPU_TAG, 0) // U54. 2764 ROM.
ROM_LOAD("mvop_4-7-86.u54", 0x000000, 0x002000, CRC(14d6596d) SHA1(c6dc579d8086556b2dd4909c8deb3c7006293816))

ROM_REGION(0x4000, "dsp_microcode", 0) // U51, 27128, 16K ROM.
ROM_LOAD("midifex_7-17-86.u51", 0x000000, 0x004000, CRC(098cc1b4) SHA1(5144ded869c3abda05a1392c31a7bdeeb166b106))
ROM_END

} // anonymous namespace

SYST(1986, midiverb, 0, 0, midiverb, midiverb, midiverb_state, empty_init, "Alesis", "MIDIverb", MACHINE_SUPPORTS_SAVE)
SYST(1986, midifex, 0, 0, midifex, midiverb, midiverb_state, empty_init, "Alesis", "MIDIFEX", MACHINE_SUPPORTS_SAVE)
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