Instructions providing new functionality for utilization by a target system program of host system container words during computer system emulation with host word size larger than that of the emulated machine

In a data processing system in which the structure and operation of a target computer system is emulated by an emulation program on a host computer system and target system memory words, each having a number of bits that are stored within host system memory words, and wherein the number of bits in each of the target system memory words is less than the number of bits in each of the host system memory words, a process for providing target system program accessibility to complete host system memory words comprising the steps of:

• A) storing in host system memory target system words such that each target system word is contained within, but does not fill, a host system word, and
• B) aligning a plurality of target system words within the same plurality of host system words such that there is a region of normally utilized bits for containing each target system word within each of the plurality of host system words, and leaving within each of this plurality of host system words a remaining number of bits, and
• C) in response to a target system instruction invoking newly defined target system functionality specified by the first target system instruction to be provided by the emulation program during emulation of a target system program:
• 1) forming an address of a host system memory word, and
• 2) providing for reading by the target system program content of the host system word including in the content all the bits of the host system memory word, including those normally utilized and also those remaining bits within the host system memory word.

In a data processing system in which the structure and operation of a target computer system is emulated by an emulation program on a host computer system and target system memory words, each having a number of bits that are stored within host system memory words, and wherein the number of bits in each of the target system memory words is less than the number of bits in each of the host system memory words, a process for providing target system program accessibility to complete host system memory words comprising the steps of:

• A) storing in host system memory target system words such that each target system word is contained within, but does not fill, a host system word, and
• B) aligning a plurality of target system words within the same plurality of host system words such that there is a region of normally utilized bits for containing each target system word within each of the plurality of host system words, and leaving within each of this plurality of host system words a remaining number of bits, and
• C) in response to a target system instruction invoking newly defined target system functionality specified by the target system instruction to be provided by the emulation program during emulation of a target system program,
• 1) forming an address of a host system memory word, and
• 2) provide for writing by the target system program into all bits of the host system memory word, including writing into both the normally utilized and also the remaining bits of the host system memory word.