ReSonique 2 Sound Card Manual

ReSonique 2 is the Izarra 3000's audio hardware: a combo card built around a Sound Blaster 16 compatible digital audio path, an OPL3 FM synthesizer, and a Yamaha ADPCM-B streaming DAC as a second, independent playback device. This manual covers what a DOS program actually finds when it probes the card.

What's on the card

Section	Compatibility	Base port	IRQ	DMA
Digital audio	Sound Blaster 16 / CT1745 mixer	`0x220`	5	8-bit: 1, 16-bit: 5
FM synthesis	OPL3 (Yamaha YMF262)	`0x388`	n/a	n/a
Streaming DAC	Yamaha ADPCM-B	`0x240` (configurable)	10	3

The digital audio and FM sections sit at their standard, fixed Sound Blaster addresses, the way real SB16 hardware does. Software doesn't need to detect them beyond the usual Sound Blaster and AdLib probes. The ADPCM-B DAC is a separate, independently configurable device window, deliberately wired to defaults (0x240/IRQ 10/DMA 3) that stay clear of the SB16 and any Windows Sound System codec sharing the same machine.

The BLASTER variable

Toka-DOS sets it in AUTOEXEC.BAT so any Sound Blaster-aware program finds the card without probing:

SET BLASTER=A220 I5 D1 H5 T6

That's base address 0x220, IRQ 5, 8-bit DMA channel 1, 16-bit DMA channel 5, and card type 6 (Sound Blaster 16): exactly the digital audio section's defaults above.

Digital audio (Sound Blaster 16 compatible)

The CT1745-compatible mixer and DSP answer at 0x220-0x22F, with the power-on IRQ and DMA defaults from the table above. These are configurable per machine through the emulator's config file or --sb-irq/--sb-dma/ --sb-high-dma flags, in case a program insists on jumpering the card somewhere else, but Toka-DOS's shipped BLASTER line always matches whatever the running configuration actually is.

FM synthesis (OPL3)

The FM synthesizer is at 0x388, the standard AdLib/OPL2/OPL3 address, and answers as a real OPL3 (Yamaha YMF262): the full four-operator instrument set on top of OPL2's two-operator patches, detected the same way real OPL3 hardware is: by reading back its status and timer registers, the classic AdLib detection routine.

Streaming DAC (Yamaha ADPCM-B)

A second, independent digital audio path: a streaming ADPCM decoder modeled on the Yamaha ADPCM-B format (the same family used in the YM2608 and Y8950), decoding 4-bit ADPCM data streamed in over DMA or a direct data port into 16-bit PCM, with its own half-buffer and end-of-buffer interrupts. This is the same shape of interrupt behavior a Sound Blaster DSP gives you, just on its own port window so it can run concurrently with the SB16 and OPL3 sections rather than competing with them. Software that specifically targets this path needs its own driver; it isn't detected through the standard Sound Blaster or AdLib probes.

What ReSonique 2 does not have, yet

The Izarra 3000's original spec sheet also lists MPU-401 MIDI and a wavetable daughterboard. Neither is implemented as hardware a guest program can program directly:

MIDI is handled on the host side instead: IzarraVM can route MIDI output either to an external MIDI device through your operating system, or to an in-process FluidSynth soundfont renderer. There is no emulated MPU-401 UART at the usual 0x330 port for a DOS program to talk to directly. A game that insists on probing for one at that address won't find it.
Wavetable daughterboard is flavor text describing where the card's design was headed, not a modeled device. There's no wavetable synthesis chip on the emulated card today.

If you're chasing down why a game's MIDI or wavetable option doesn't light up, this is why. Check the troubleshooting page for what to try instead (OPL3 FM is always a safe fallback for MIDI-style music in period DOS games).