The first prototype of Mackerel-30 is alive! After many hours of soldering, updating Verilog, and modifying memory maps and Makefiles, the 68030 is up and running. Better yet, it's running the same bootloader code as Mackerel-08 and -10 and loading programs over serial. Since the 68030 is more or less a superset of the earlier CPUs, very little C code needs to change from previous iterations of Mackerel.

So far I have verified the basics of the system. Only the ROM, SRAM, and DUART have been tested, but there's enough glue logic implemented to run the bootloader and handle vectored interrupts from the DUART.

Seeing a new design come to life really never gets old. That said, this is a prototype and there are already some problems. For one, the serial header is backwards from previous Mackerel hardware. This caused a slight panic when the code appeared to be running, but no serial output was displayed. Fortunately, flipping the USB-serial adapter solved that issue.

I also managed to export the Gerbers without noticing that the VIN pin of the 3.3v regulator was not connected to anything. I need to figure out why KiCAD didn't complain about this, but the 3.3v power is not actually needed for the board to run, it's just there for external hardware, so no harm done. It's also easy enough to bodge the VIN pin to a nearby 5v rail if necessary.

I haven't hooked up the FPU yet, but I am missing A13-A15 pins on the glue CPLD. I think these are required as part of address decoding for the FPU, so they may need to be bodged in.

Finally, there are a few footprint issues. The mounting holes for the 72-pin SIMM are not all sized correctly, requiring some "plastic surgery" to solder in the socket.

The DIN 41612 connector footprint also has issues. The holes are all way too small to fit the pins of the connectors I have. This is not a custom footprint, it was pulled from the KiCAD library, so it's possible I just have non-standard connectors, but either way, it makes the expansion header pretty unusable.

With the basics working, my plan is to finish assembly and test the DRAM, IDE, and FPU. If at least the DRAM and IDE are functional, I should be able to start on the Linux port. If I find any showstopping issues, I guess Linux will have wait for the next revision.