User talk:Tom94022/Sandbox/CKD History

Page move

Hello. I moved the page you created at Tom94022/Sandbox/CKD History to User:Tom94022/Sandbox/CKD History. —Largo Plazo (talk) 20:55, 17 August 2015 (UTC)

CKD History

1.) Search commands are control commands.

2.) The section on ECKD is missing. It came in support of the SMB on the 3880; while the 3880-11 and 3880-13 have caches and new CCW opcode, they did not have locate and one didn't even have Define Extent.

IBM (March 1982), "Commands", IBM 3880 Storage Control Model 11 Description (PDF), First Edition, p. p. 13, GA32-0061-0, Four new commands have been added and are executed only by the paging storage director. They are Discard Block, Set Paging Parameters, Sense Subsystem Counts, and Sense Subsystem Status. Discard Block and Set Paging Parameters are executed only in paging mode. The other two commands are executed only in direct mode. {{cite book}}: |page= has extra text (help)

IBM (June 1982), "Commands", IBM 3880 Storage Control Model 13 Description (PDF), First Edition, p. p. 11, GA32-0067-0, Five new commands have been added: Set Path Group ID and Sense Path Group ID, which can be used in conjunction with Device Reserve and Device Release commands, and Define Extent, Set High-Performance Storage Limits, and Set Subsystem Mode commands which are used in controlling cache {{cite book}}: |page= has extra text (help)

3.) Additional features to mention are remote mirroring, PAV and EAV.

Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:32, 19 August 2015 (UTC)

Don't forget to mention dropping Record Overflow. Also, there should be some mention of configuring 3350 and 3390 to have a different logical track size from the physical size. Shmuel (Seymour J.) Metz Username:Chatul (talk) 22:49, 20 August 2015 (UTC)

The initial 360 announcement had a 7320 drum on the 2841; this was later replaced by the 2303 drum. Shmuel (Seymour J.) Metz Username:Chatul (talk) 19:25, 26 August 2015 (UTC)

ECKD History

The ECKD commands on the 3880-1, -2 and -3 were only available when the speed matching buffer (SMB) was installed. Both the 3880-11 and the 3880-13 had a cache. I'd suggest a link to the 3880 manual for the ECKD commands and a link to the 3880-11 manual.

The description of ECKD is incorrect. What the feature does is to provide additional CCW opcodes that allow the programmer to replace a single CCW with multiple CC?Ws, sucvh that the mechanical delay is handled asynchronously between CCWs, e.g., by a LOCATE chained to a Read.

When did PDS assist come along? Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:09, 26 August 2015 (UTC)

Unlike the 3880-13, the paging director of the 3880-11 only caches 3350 drives. Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:59, 26 August 2015 (UTC)

Quotations in references

What is your policy on using quote= in {{cite book}} as opposed to paraphrasing the text inline? Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:09, 26 August 2015 (UTC)