The concept of a single instruction to load or store multiple registers is much much older than the 68000 architecture. It goes back to 1964 when IBM announced the S/360 architecture. The instructions were called LM (load multiple) and STM (store multiple). It's probably an older concept than that but I'm not familiar with 1950's computer architecture.

Here is LM and STM used in an IBM assembler calling convention: http://en.wikipedia.org/wiki/IBM_Basic_assembly_language_and...