April 26, 1989 The SCSI-2 CAM (Common Access Method) Committee meeting of April 13 was held at the Sheraton Denver Airport. The following attendees were present: M. Aarons EMULEX J. Polonsky SMS D. Allan ENDL K. Post FUTURE DOMAIN J. Armstrong NCR T. Putnam OPTOTECH C. Ballard BALLARD SYNERGY D. Rawcliffe SEAGATE D. Brockus EMULEX T. Reichert INTERACTIVE SYSTEMS E. Harper COLORADO MEMORY SYSTEMS L. Robinson STORAGE DIMENSIONS W. Ihde LMS OSD S. Shah WESTERN DIGITAL A. Jardetzky OLIVETTI T. Shea ADAPTEC R. Lewis EMULEX S. Smyers AMD C. Linsley SMS B. Snively SUN MICROSYSTEMS P. Manley SYQUEST TECHNOLOGY G. Stevens ONTRACK COMPUTER G. Marazas IBM R. Tewell COLUMBIA DATA G. Milligan CDC IMPRIMIS T. Treadway DPT T. Murray NCR D. Trupski OLIVETTI R. Perry SEAGATE The acronyms of CAM have proven a barrier to explaining its capabilities, so an attempt was made to define less confusing terms. The OSD is not an independent control block but a required part of a TCB (Transport Control Block) or an SCB (SCSI Interface Module Control Block) and its associated CDB (Command Descriptor Block). A CCB (CAM Control Block) describes the structure needed for a complete request, either Transport or SIM. Transport Request SIM Request +-----+-----+ +-----+-----+-----+ | OSD | TCB | | OSD | SCB | CDB | +-----+-----+ +-----+-----+-----+ Rick Tewell described the Transport Module as an entity that has a split personality. - As a verb it is responsible for performing the act of linking the user (kernel, application, whatever) to the SIM. - As a noun it provides services that are non-SCSI, such as HBA reset, routing, generic read/write, et al. Rick used the term Transporter to describe the noun identity, and ran into flak over it being able to handle generic requests. Not all environments need this capability, but it is the one which produces the highest volume of inquiries on what CAM is all about. It is needed by the software vendors and application writers who are poorly represented at CAM Committee meetings. It was agreed that this functionality "could" be made available, but it is not a requirement. It will be defined as part of the CAM. Ron Perry described some of the difficulties in defining how the SIM gets initiated in a DOS environment. More work will be done in this area with help from Jerry Armstrong and Shishir Shah. Tom Shea described the method for calling between modules in an OS/2 environment, and the minimum requirements in control values and addresses. Todd Reichert described the requirements that the Unix environment would want of the SIM. Shishir objected to resource allocation being in the SIM, as it was a function which properly belonged in Transport so that SIMs could be kept OS-independent. This is an issue that may affect the existing SIM definition, and will take some working out. Clint Ballard suggested adding a partitioning capability to complement the common algorithm for Cylinder-Head-Sector calculations. Its value would be in permitting unlike environments e.g. Macintosh and IBM PC, to share the same disk. Gene Milligan described the ATA (AT Bus Attachment) specification which describes the Task File Register operation of PC AT Hard Disk controllers. Tom Treadway described EATA (Enhanced ATA) which describes how SCSI commands are transferred as data through the ATA. NOTE: There have been two working groups since the last CAM meeting, and the dedicated efforts of Gene and Tom have produced a viable working document. The ATA is in the format of a proposed standard, and the EATA will be merged in as one of the open sections. Lance Robinson supplied one more representation of the way in which the CAM functions can be graphically described. There was less disagreement with his interpretation than on any other to date, so we may be on to a winner here. When he was at Comdex earlier in the week, Lance spent some time at the IBM booth where he learned that the IBM approach to supporting SCSI (IBM had two HBAs on demonstration) appears to be very close to that of the CAM; generic requests are made to disk and tape, and SCSI-specific to other devices. All of the documents provided at the AT working groups and this meeting are attached. Information on ongoing efforts can be found on the SCSI BBS. The SCSI BBS (316-636-8700), Area 13 is the clearing house between members working on proposals. Proposals etc will be in the Files section and short exchanges are in the Message section. Future Meetings: Air fares are the most expensive part of attending meetings, and in recent months we have all noticed a general increase in costs as the airlines cut back on their discounted travel programs. John Lohmeyer and Clint Ballard have arranged special fares with American for the meetings they are hosting and this spurred me to investigate setting up permanent travel arrangements. The airlines which have agreed to provide special air fares for all CAM meetings (as well as other ANSI meetings and working groups) are United and Northwest. The arrangements for each airline are the same. - Call a special 800 number which connects you to the Meetings desk. - The Meetings desk has limited hours, so no late night calling! - Supply the Travel ID Number for the airline you are calling. - Receive a flat 40% discount on regular air fares. - Receive an additional 5% on discounted fares. - Make arrangements at least 7 days in advance. - You can be ticketed by your own agent. Travel agents can use the number but they do not seem to like calling the Meetings desk - it takes longer than making reservations on their terminals and the airfare is lower (smaller commission). Airline Phone Number Meeting ------- ----- ------ ------- United 800-521-4041 413TA All Northwest 800-328-1111 15201 All American 800-433-1790 S05Z9GQ 5/10/89 only " " 0269VB 6/ 8/89 only There is a similar problem with hotel arrangements. At the Denver Sheraton only 6 nights were credited against the cost of the meeting room but we had 28 nights between the attendees. Some fast talking to the Sales Desk saved the cost of the conference room. Our hosts are committed to a minimum number of room nights which are used to offset the cost of the conference rooms. Please make sure the hotel is given the name of the host organizing the meeting, even if it means placing the call yourself. Date Host City Hotel Hotel Phone ---- ---- ---- ----- ----------- 5/10/89 NCR Wichita Hilton Hotel 313-686-7131 6/ 8/89 Ballard Synergy Cupertino Cupertino Inn 408-996-7700 7/12/89 AT&T Chicago Ramada O'Hare 800-272-6232 Meetings are currently scheduled through July, and the calendar for the remainder of the year will be fixed at the May meeting. The schedule calls for one meeting being set immediately after the SCSI Working Groups (the odd months), and the other set midway between them. Any company that is willing to host, please call me at 408-867-6630 or fax at 408-867-2215. I should apologize to all for the late delivery of these minutes and the attached documents, but I do have an excuse. The day after our meeting I was committed to a 25th Wedding Anniversary trip (an investment in the next 25 years), and immediately following was ANSI plenary week. I. Dal Allan