The next WonderMCA board is on its way — the new revision is currently being manufactured by JLCPCB. This is the biggest step the project has taken so far: it sets out to fix every issue from the initial release while adding a whole stack of new capabilities that push the card much closer to its final form.
What’s new
- RP2350 design is now using 0603 footprint
- A bigger brain for the bus — new CPLD. The card moves to the ATF1508-10 in a PLCC84 package, giving plenty more room for the Micro Channel glue logic.
- In-circuit CPLD programming. A TAG-Connect footprint lets the CPLD be reprogrammed in place — no more fiddling with the chip to push a new logic build.
- A full 16-bit data path. A new mux plus an additional bidirectional buffer let the card properly handle the 16-bit MCA data bus.
- More signals on the high GPIO bank. ADL and CMD are now routed to the high bank of the RP2350 GPIO.
- WiFi RM2 instead of ESP32. The wireless side switches to the RM2 module — cleaner integration and better support.
- CHRESET handling. Proper handling of the channel reset signal.
- Sound onto the MCA bus. Audio can now be driven onto the Micro Channel bus itself.
- Front-panel-ready status LED. An onboard LED, plus a jumper to deport it to the front panel.
What’s fixed
- CMD signal taken straight from the bus. The CMD line now comes directly from the MCA bus instead of being derived.
- Better analog-ground isolation for cleaner audio.
- New sound jack connector.
- New battery holder.
- Corrected pull-up resistor.
Boards are in production right now — I’ll post build and bring-up notes as soon as they land on the bench. As always, you can follow the journey on the blog, and if you’d like one when it’s ready, join the WonderMCA waitlist.