PROJECT PROPOSAL FOR MAINTENANCE OF THE SCSI STANDARD 1. IDENTIFICATION OF THE PROPOSED STANDARD 1.1 TITLE: SMALL COMPUTER SYSTEM INTERFACE - 3 (SCSI-3) 1.2 PROPOSER: X3T9 1.3 DATE SUBMITTED: 11 DECEMBER 1987 2. JUSTIFICATION OF THE PROPOSED PROJECT 2.1 NEEDS: With the development of SCSI-1, it was found that the SCSI standard was attracting new applications as fast as it could be documented. This raised the potential of not being able to complete a published standard, as new applications resulted in additions to the draft standard. Continued development beyond the basic definition would unfairly delay the early developers if they had to wait for documentation of the last application requirements. Consequently the SCSI-2 project was proposed and subsequently authorized. Utilization of this development and publication strategy has been very beneficial in both the realization of products based upon the published standard and for it's further growth. While the SCSI-2 draft standard has a much broader capability than the published SCSI-1 standard, it has maintained a high degree of compatibility with the original standard. However, again the industry faces a significant need to have the standards community publish SCSI-2 to provide a benchmark for the current state of SCSI art. As in the previous instance, the revised version of SCSI should be published as SCSI-2 and a number of capabilities requiring further development work should be made a part of a SCSI-3 development program. 2.2 Recommended Scope of the Standard: The proposed SCSI-3 Standard should maintain a high degree of downward compatibility with SCSI-2 while providing documentation for new capabilities including the following candidates: a- Faster bus transfers increasing the asynchronous transfer rate from approximately 1.5 million bus transfers per second to approximately 3 million bus transfers per second. b- Faster bus transfers increasing the synchronous transfer rate from approximately 4 million bus transfers per second to approximately 8 million bus transfers per second. c- Wider bus options, maintaining downward compatibility with the 8 bit bus but providing wider options such as 16, 24 or 32 Bits. d- Expanded bus connectivity options to increase the number allowed of connected SCSI bus devices from 8 to 16 or more. e- Optional higher density/miniaturized connectors to allow more compact applications and or wider busses in the same or smaller devices. f- Other capabilities which fit within the general application scope of SCSI that may be proposed during the development phase by participants in the project. g- Maintenance of the SCSI standard that may result from further results of implementation of SCSI-1 and/or SCSI-2. 2.3 EXISTING PRACTICE IN THE AREA OF THE PROPOSED PROJECT: The proposed project involves evolutionary expansion of the present SCSI -1 Standard and the completing SCSI-2 draft proposed Standard. In addition complementary work is underway in the X3T9 project for faster and wider IPI. That work can be used as a helpful input to SCSI-3. 2.4 EXPECTED STABILITY OF THE PROPOSED STANDARD WITH RESPECT TO CURRENT AND POTENTIAL TECHNOLOGICAL ADVANCES: The nature of the proposed project is to help keep SCSI with an upward , highly compatible growth path. This will help insure that current investments in SCSI are provided with more stability in face of technological developments. 3. DESCRIPTION OF THE PROPOSED PROJECT a- Solicit continuing participation by the present SCSI-2 participants through X3T9.2 procedures and new participants through press releases. Invite comments by end-user organizations. Invite proposals from SCSI Initiator and Target vendors, SCSI system integrators, SCSI software developers and other organizations that may have a contribution to the development of a viable SCSI-3 Standard. b- Establish functional requirements for SCSI functional additions along with functional downward compatibility requirements. c- Maintain a process for accepting proposals and maintenance requirements for consideration. d- Using basically the same process as has worked well for SCSI-1 and SCSI-2, complete development of SCSI-3. e- Consider the results of SCSI-3 testing as may be available to the committee through the voluntary efforts of various participants in X3T9 and its assigned task group. f- Submit the SCSI-3 draft proposed Standard to X3 for further processing. 3.4 RESOURCES - INDIVIDUALS AND ORGANIZATIONS COMPETENT IN THE SUBJECT MATTER: Task Group X3T9.2 has a large and active membership of participants that have proposed their desire to help develop a SCSI-3 Standard. 3.5 RECOMMENDED X3 DEVELOPMENT TECHNICAL COMMITTEE: It is recommended that the development work be done within X3T9.2 which has already developed SCSI-1 and is completing SCSI-2. 3.6 ANTICIPATED FREQUENCY AND DURATION OF MEETINGS: The SCSI task group X3T9.2 meets for two days bi-monthly. Specific task working group meetings are called as may be required for one to three days between the regular meetings but their results are not binding. 3.7 Target Date for Submission of a dpANS to X3: Submission is targeted for February 1990. 3.8 Estimate Useful Life of the Standard: Through evolutionary enhancements to the SCSI Standard as has been done by SCSI-2, now by the proposed SCSI-3, and as could be anticipated by SCSI-4, the useful life of the Standard can reasonably be expected to exceed 15 years. 4. IMPLEMENTATION IMPACTS 4.1 IMPACT ON EXISTING USER PRACTICES AND INVESTMENTS: The proposed SCSI-3 Standard should provide an upward growth path that should be complementary to the 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 SCSI-3 Standard should provide an upward growth path that should be complementary to the existing supplier products and support. It is likely that any isolated negative impacts would occur in any case through non- standard evolution or revolution. 4.3 TECHNIQUES AND COST FOR COMPLIANCE VERIFICATION: The committee will consider the results of SCSI-3 testing as may be available to the committee through the voluntary efforts of various participants in X3T9 and it's assigned task group. With this method all costs are born by the organization of 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 to be introduced by the SCSI- 3 project that are not already attendant with SCSI and in accordance with accepted X3 patent policies. 5. CLOSELY RELATED STANDARDS ACTIVITIES: 5.1 Existing Standards: a- SCSI-1 b- SCSI-2 5.2 X3 Standards Development Projects: a- X3T9.3 IPI 5.3 X3/Sparc Study Groups: None. 5.4 Other Related Domestic Standards Efforts: None. 5.5 ISO Standards Development Projects: SCSI 5.6 Other Related International Standards Development Projects: None 5.7 Recommendations for Close Liaison: a- X3T9.3 b- JC1/SC13