The PDS sounds like a fairly typical console devkit of the time: basically just a larger, more powerful system to host the build toolchain and an in-circuit emu

The PDS sounds like a fairly typical console devkit of the time: basically just a larger, more powerful system to host the build toolchain and an in-circuit emulator you plugged into the cartridge slot. I remember an interview with the Mega Man devs in which they mentioned they used an HP 9000 workstation with an ICE simulating a Famicom cartridge to develop the game. Fancy devboxes with custom console builds, like the PS2 TOOL, would come later (probably necessary when cartridges were phased out).