Ha H3NRY, you're right, it is merely a trip down nostalgia lane. But then this entire site is a trip down nostalgia lane. For me, there was a period of about a year when the 128K Mac was the greatest thing I'd ever seen, and despite its limitations, obvious even then, I couldn't wait to play with it every chance I got. When I finally got my hands on a 512K, I never looked back until some time later as nostalgia got its rusty hooks into me. The focus on limiting RAM to 128K is to experience an authentic experience. Your idea about a RAM Disk is a good one. Unfortunately, it won't work with the earliest system software. Then again, I have no idea how the Plus hardware will respond to operating under a 64K ROM.

All good food for thought and tinkering.

Now, this has got me thinking about ultimate compatibility in one box. I'm wondering if a SWIM chip could be substituted for an IWM chip in a Mac Plus, if the SWIM ROM code were patched in via a system INIT, like the HD20 & HFS code is patched on the 64K ROM? On the other hand, if that were possible, I would think someone would have come up with this solution for the Plus, considering the volume of them sold and their continued viability into the mid-90s.