Rather than design a bare minimum prototype for Mackerel-30, I decided to take a bit more risk and incorporate most of features I want from the start. Moving from the 68008 to the 68010 was a reasonable step up in complexity. Jumping to the 68030 presents another significant leap with 32-bit buses and more complicated control logic. In some ways, it's actually easier to deal with though. The dynamic bus sizing removes the requirement for 16-bit ROM and RAM chips. A single 8-bit ROM and SRAM should be enough to bootstrap the system.

Besides the new CPU, I've included a few other hardware upgrades. I'm looking forward to getting the MC68882 FPU up and running. It should be supported by Linux and might give a boost in performance for things like scripting languages or graphics support if and when I get to those.

I've also upgraded to 72-pin SIMMs for the DRAM. Each SIMM is 32-bits wide which makes the wiring straightforward and requires only a single module. The available capacities are also quite a bit higher than 30-pin modules, going up to at least 128MB. The DRAM controller will be adapted from the one I designed for Mackerel-10.

The only piece I have not included in this first prototype is networking hardware. I'm still exploring some options in this area and I'm not ready to commit to one design. Once the base system is brought up, I plan to build a network card to connect to the expansion header.