Apple II's SD Music Deluxe card just got better Mockingboard emulation

Firmware V1.0E for the SD Music Deluxe card is now available, bringing more accurate Mockingboard emulation to the Apple II. Creator Ian Kim released the update yesterday to refine how the hardware handles classic audio output.

The SD Music Deluxe card is an enhanced, high-quality Mockingboard emulator for the Apple II series. It includes a Yamaha YMF262 (OPL3) chip that delivers 18 voices and stereo sound. The hardware also provides built-in General MIDI and MT-32 banks alongside standard Apple II speaker mixing. The Yamaha YMF262 is the same chip that powered the Sound Blaster 16 on early DOS PCs. Having that level of FM synthesis inside an Apple II opens up entirely new avenues for homebrew development and music playback. The built-in banks mean the card can handle complex arrangements that go far beyond the original Mockingboard specifications.

The original Apple II shipped in 1977 with a simple 1-bit speaker. That internal speaker was fine for basic error beeps but terrible for actual music. Third-party companies eventually stepped in to solve the problem. Sweet Micro Systems released the Mockingboard in 1983 to give the computer proper multi-channel sound. Games like Ultima III and Skyfox used the Mockingboard to produce audio that the stock Apple II could never dream of generating. The SD Music Deluxe card recreates that expansion today while adding modern FM synthesis capabilities on top of it.

Chasing the AY-3-8910

This specific firmware update targets the Mockingboard side of the equation. The volume balance is now adjusted to more closely match the characteristics of the actual AY-3-8910 sound chip.

General Instrument designed the AY-3-8910 in 1978. It became the backbone of early 1980s computer audio. The chip powered the Intellivision console, the Vectrex, and home computers like the MSX and ZX Spectrum. The Mockingboard used these exact chips to generate its three distinct sound channels and noise effects.

The new V1.0E firmware tweaks the volume, envelope, and noise responses to mirror that original silicon more accurately. The default sound output is also smoother and less harsh overall. The update corrects a few minor operating stability issues in the background as well.

Pull the block, wait for the chime

Applying the update requires a bit of manual labor. You have to power down the Apple II and physically remove the S/W block from the card. You then install the card into Slot 4 and boot the system using the firmware update disk image.

Once the update finishes, the card plays a literal "Ding-Dong" completion sound to let you know it worked. You then power the system back down, reinstall the S/W block, and go back to playing your vintage software.