1. Identification of Proposed Project 1.1 Title: Memory Model Interface 1.2 Proposer This project is proposed by the X3T9 Technical Committee. For additional information, please contact John B. Lohmeyer, X3T9.2 Chairman, at NCR Corporation, 3718 N. Rock Rd., Wichita, KS 67226 (Phone: 316-636-8703 Fax: 316-636-8889) or Dal Allan, X3T9.2 Vice-Chairman at ENDL, 14426 Black Walnut Ct, Saratoga, CA 95070 (Phone: 408-867-6630 Fax: 408-867-2115). 1.3 Date Submitted: August 23, 1991 1.4 Project Type: Development 2. Justification of Proposed Standard or Technical Report 2.1 Needs The emerging class of small disk drives are so small that they can be considered for direct attachment to the circuit board of a computer system. Traditionally, disk drives have been cabled devices, and moving to the circuit board opens up the need for another form of interface that is well-suited to that application. Circuit boards have used semiconductor random access memory for years, and it is familiar to all system designers, even those unfamiliar with the cabled channel attachment of disk drives. Providing a memory model interface widens the application of disk drives to application areas outside computer systems. 2.2 Recommended Scope of Standard or Technical Report The Memory Model Interface is intended to provide an alternative means of attaching disk drives which is better suited to direct board mounting than the channel model of the X3.129, X3.130, X3.131, X3.132, X3.147 standards for SCSI (Small Computer System Interface) and IPI (Intelligent Peripheral Interface) as well as X3T9.2/90-143, the draft standard for ATA (AT Attachment). Functions which will be considered for incorporation include: a) Addressing storage on a byte, word, or block basis. b) Transferring data in a similar manner to that used by semiconductor memory. c) Other capabilities which fit within the general scope of implementing the Memory Model Interface Interface on a broader range of applications. This proposed standard will require changes in the traditional method of supporting disk drives in order to take advantage of the functionality that will be provided by the Memory Model Interface. 2.3 Existing Practice in Area of Proposed Standard or Technical Report Semiconductor memory devices utilize a model to address memory which differs from that of channels. A recent class of devices are memory cards which are removable devices that can be used to extend board-installed memory. 2.4 Expected Stability of Proposed Standard or Technical Report with Respect to Current and Potential Technological Advance The nature of the proposed project is to insure that small disk drives can be integrated in a manner which expands the alternatives available to host system manufacturers and storage subsystems. 3. Description of Proposed Project 3.1 Type of Document (Standard or Technical Report): Standard 3.2 Definition of Concepts and Special Terms (if any): none 3.3 Expected Relationship with Approved X3 Reference Models (e.g., DBMS, OSI) The Memory Model Interface is for use in closed systems. 3.4 Recommended Program of Work The following program of work is planned for the Memory Model Interface standard: - Solicit participation from the SCSI, IPI, and ATA participants and new participants through X3T9.2 procedures and through press releases. Invite comments by end-user organizations and invite proposals from organizations that may have a contribution to a viable Memory Model Interface standard. - Establish functional requirements for Memory Model Interface functional additions. - Prepare a draft standard based on proposals submitted and other information gathered during the initial investigation. - Consider the results of Memory Model Interface testing as may be available to the committee through the voluntary efforts of the various participants in X3T9 and its assigned task group. - Submit the draft proposed standard to X3 for further processing. 3.5 Resources - Individuals and Organizations Competent in Subject Matter The current membership of X3T9.2 includes representatives from all parts of the computer industry from semiconductor chip manufacturers to large mainframe system manufacturers as well as Government agencies. The members of X3T9.2 have expressed their desire to participate and cooperate in the development of this proposed standard. There are sufficient resources to complete the development of this standard without delaying work on other standards. 3.6 Recommended X3 Development Technical Committees (Existing or New) It is recommended that the development work be done in task group X3T9.2. 3.7 Anticipated Frequency and Duration of Meetings Task group X3T9.2 meets for two days bi-monthly. Specific task ad hoc groups are called as may be required for one to three days between the regular meetings but their results are not binding. 3.8 Target Date for dpANS to X3 (Milestone 10): April 1993 3.9 Estimated Useful Life of Standard or Technical Report It is anticipated that this standard will have a life of over 10 years. 4. Implementation Impacts 4.1 Impact on Existing User Practices and Investments The proposed Memory Model Interface standard will provide an upward growth path which complements existing practices and investments. It is likely that any isolated negative impacts would occur in any case through non-standard evolution or revolution. 4.2 Impact on Supplier Products and Support The proposed Memory Model Interface standard will provide an upward growth path which complements existing practices and investments. It is likely that any isolated negative impacts would occur in any case through non-standard evolution or revolution. 4.3 Techniques and Costs for Compliance Verification The committee will consider the results of Memory Model Interface testing as may be available to the committee through the voluntary efforts of the various participants in X3T9 and its assigned task group. With this method all costs are borne by the organizations of the various participants and have for the most part been mainly an adjunct of their normal development costs. 4.4 Legal Considerations No new legal considerations are expected that are not already in accordance with accepted X3 patent policies. 5. Closely Related Standards Activities The standardization effort on memory card interfaces is being pursued by the PCMCIA (Personal Computer memory Caird International Association), and some members of IEEE have shown interest in memory-model interfaces because the small drives can be mounted on circuit boards which contain memory buses. 5.1 Existing Standards: none 5.2 X3 Standards Development Projects none 5.3 X3/SPARC Study Groups: none 5.4 Other Related Domestic Standards Efforts: none 5.5 ISO Standards Development Projects It is anticipated that this standard will be proposed to JTC1/SC25/WG4. 5.6 Other Related International Standards Development Projects: none 5.7 Recommendations for Coordinating Liaison: none 5.8 Recommendations for Close Liaison: Establish liaison with the IEEE FutureBus and Microcomputer working groups to expand the number of system manufacturers that may have an interest in a the Memory Model Interface.