https://peertube.dngr.us/videos/watch/57c25467-72fc-4404-a812-b249d814c6e0 This film "IBM Confidential — IBM System/360 Read Only Storage" (1964 era) was produced for internal use at International Business Machines. The film discusses the implementation and advantages of read-only storage (readon storage) in the System/360. (The System/360 was a system of mainframes introduced in 1964 that ushered in a new era of compatibility in which computers were no longer thought of as collections of individual components, but rather as platforms.) The film covers the replacement of conventional circuitry with readon storage, its role in ensuring compatibility with 147,000 series systems, and its application in various models like the Model 30, 40, 50, 60, and 62. Compatibility, emulation, and simulation are defined, highlighting how readon storage allows for program compatibility and the best system price performance. Detailed descriptions of different readon storage devices are provided. 00:00 Speaker introduces the topic of readon storage in System 360. 0:31 - Discusses advantages and primary purposes of readon storage. 1:00 - Readon storage replaces conventional circuitry. 1:11 - Provides compatibility with 147,000 series systems. 1:35 - Model 70 uses conventional circuits. 1:48 - Example of readon storage in Model 30. 2:04 - Readon storage replaces tubes, wiring, etc. 2:21 - Introduction of terms: microinstruction, microprogramming. 2:28 - Five elements of system control. 3:09 - Explanation of program cards and capacitive plates. 4:18 - Microinstructions: internal steps for machine operations. 5:00 - Readon storage ensures timed impulses and reliable functioning. 5:44 - Formation of readon capacitive storage device. 7:04 - Other readon storage devices in Model 40, 50, 60, 62. 8:19 - Transformer readon storage in Model 40. 9:18 - Edge plate readon storage in Model 50, 60, 62. 9:57 - Conclusion on the role of readon storage in controlling System 360. 11:05 - Various registers will store data (e.g., A, B, X, Y, P, Q) and a sum register for results. 11:22 - Simple data flow control using micro instruction routines. 11:33 - Example of an add instruction (A to B, store in C) for System 360. 11:53 - Model 30 microprogramming under readon storage address control register. 12:06 - Sequencing through fixed routines or conditional branches. 12:26 - Reading a field out of storage by closing specific gates. 12:59 - Regenerate the A field. 13:34 - Storing the A field in a hold register 13:54 - Reading the B field from main storage by closing gate number one. 14:21 - Adding A to B and executing the arithmetic operation. 14:50 - Storing the sum and regenerating it into core storage. 16:01 - Flexibility in handling overflows, underflows, and internal controls. 16:20 - Readon storage usage in Model 30 with approximately 4,000 words. 16:52 - Transformer readon storage in Model 40 and other types in Model 50/60/62. 17:16 - Compatibility feature 18:06 - Additional readon storage unit 18:47 - 360 data flow paths used without adding new internal circuits. 19:14 - Advantages of System 360 and readon storage. 19:38 - Control of the system and interpretation of instruction sets. 20:03 - Discussion of handling compatibility terms in the marketplace. 20:08 - Explanation of compatibility and hardware compatibility features for Model 30. 20:38 - Introduction of the term "emulation" and its various uses in readon storage and SLT circuits. 21:09 - Definition of "simulation" as interpreting any instruction set from another machine using software. 21:37 - Advantages of readon storage 22:09 - Provides the best system price performance and balanced throughput performance.23:06 - Importance of compatibility with proven object programs of the 147,000 series. 23:26 - Parity validation. 24:03 - Reduces CPU requirements for the control function. 24:16 - Series of slides to summarize and illustrate readon storage devices in System 360. 24:36 - Example of System 360 circuits and control in Model 70 and smaller systems. 25:04 - Logical functions and data flow control using readon storage units in smaller systems. 26:02 - Exploded view of microprogram card capacitor readon storage in Model 30. 26:23 - Full module of readon storage in Model 30 and ease of inserting microprogram cards. 27:26 - Transformer readon storage micro instruction tape. 27:56 - Core inserted through tapes in assembly, plugged into logic circuits and data flow. 28:28 - Bit plane for balanced capacitor readon storage in models 50, 60, and 62. 29:22 - Standoff view of readon storage in Model F and large circuit boards with SLT circuits. 29:50 - Exploded view with readon storage location and function. 30:19 1620 emulator for Model 30. 30:53 31:11 - Conclusion This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit http://www.PeriscopeFilm.com Source: https://www.youtube.com/watch?v=gcc_SAy-I80 Mirrored from Periscope Film (https://www.youtube.com/@PeriscopeFilm) Sat, 13 Jun 2026 13:28:44 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.dngr.us https://peertube.dngr.us/lazy-static/avatars/41a6fee9-7f57-42d0-a5fc-5db4f1af2e31.png https://peertube.dngr.us/videos/watch/57c25467-72fc-4404-a812-b249d814c6e0 All rights reserved, unless otherwise specified in the terms specified at https://peertube.dngr.us/about and potential licenses granted by each content's rightholder.