Adafruit Fruit Jam: Mac Emulation, DVI, and Speaker Selection

Audio Board Finalization

• ✅ The TLV320DAC3100 audio board design has been finalized, resolving previous headphone and grounding issues.
• 🚀 This board is now ready for PCB production and will be available in the store soon.
• 💡 The same audio amplifier is crucial for the Fruit Jam board completion.

Fruit Jam Board Revisions

• 🛠️ The Fruit Jam board has been updated to Rev B, incorporating several fixes and tweaks.
• 📌 Key changes include expanded GPIO (2x16 pins), a relocated speaker, removal of the IPY connector, and the addition of an ESP32-C6 for Wi-Fi/BLE.
• ✨ Other improvements are an IR input, repositioned HDMI/DVI port for more space, and a fix for a USB hub power fluctuation issue.

Mac Emulation with Marchintosh

• 🍎 The video demonstrates Jepler's pico-mac emulator port running on the Fruit Jam board, featuring hardware DVI output.
• 💾 The emulator utilizes 4MB of PSRAM (expandable to 8MB) and can run System 6 (and System 7, though slower) from images loaded on an SD card.
• 🔊 Audio is now working for many games, enhancing the retro computing experience.

Advanced Audio Emulation Challenges

• ⚠️ While basic audio works, more advanced 68k Mac audio using the 6522 VIA timer chip is not yet fully emulated.
• 🔬 This un-emulated chip handles specific timing and data shuffling, causing some games like Glider to lack sound.
• ⚙️ Emulating the VIA chip presents challenges, including managing IRQ frequency to avoid hard faults.

Speaker Component Selection

• 🔍 A through-hole speaker was selected for the Fruit Jam board using Digi-Key's search interface.
• 📏 Criteria included a diameter of 20mm or less, 4-8 ohms impedance, and a PC pin type for easy soldering.
• ✅ The chosen speaker, CVS-158, is a 15mm, 8-ohm, 0.3W component, suitable for onboard audio in the limited space.