Two unique instructions for the instruction set of a target 36-bit machine
which is emulated on a host 64-bit machine are provided in order to
achieve visibility, to an emulated application program, of a "containing"
word stored in the memory of the host machine. A "LOAD64" instruction
loads the emulator memory location representing an emulated "Q"
(supplementary accumulator) register with the "normal" 36-bits of the
containing word. At the same time, the "upper" 28 bits of the 64-bit
containing word is copied into the emulator memory location representing
an emulated "A" (accumulator) register. Thus, the emulated 36-bit machine
"sees" and can examine the 64-bit word in its entirety. A "Store64"
instruction stores the emulated "Q" register contents into the lower
36-bits of the 64-bit containing word, and at the same time stores the
lower 28 bits of the emulated "A" register contents into the upper 28
bits of the 64-bit containing word.