I've known about this Nested Volume Manager article (by Mike Schuster of Adobe, April 1986) since 2007. I've always thought it was a neat concept, which I will summarize thusly:
Format a HDD like the Apple HD20 (serial interface) and then use the special Desk Accessory (DA) and driver...
This can help you get quickly set up for Macintosh C programming, targeting a wide range of macs (System 7.5.5 all the way down to the earliest macs around System 1).
The included resources are:
The compiler/linker/builder of choice is Symantec THINK C v6.0.
Resource editor done with ResEdit...