The first question is how old. In general, a channel connects to a control unit, which either connects to an I/O device or which also serves the role of an I/O device. A complication is that some processors had an option for an integrated adapter that served the role of both controller and device, e.g., IFA, ISC.
The 3830 or 3880 was the CU, since it was what connected to the channel. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of R.S. <r.skoru...@bremultibank.com.pl> Sent: Wednesday, May 15, 2019 8:59 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Ancient DASD connectivity (this is mostly historical question) I'm trying to understand the role of old boxes in DASD connectivity. From IODF/HCD point of view we have CPC-channels-CU-some_cable-DEVice Nowadays in real world we have CPC-ficon-DASDbox and DASDbox is both CU+DEV (emulated). In the old days there was a Storage Control Unit, i.e. 3830 and disk controller within disk cabinet, i.e. 3350-A2 So, we have CPC-cable1-3830-cable2-3350A2controller-internal_cable3-disk. I'm trying to understand separation of duties between 3830 and 3350A2 controller. What was defined as CU - it was 3830 or controller within 3350 cabinet? Which cable was a channel (Bus&Tag)? I guess it is "cable1" connecting CPC and 3830. Not to mention that some old reference manual's diagram shows yet another box between CPC and 3830 SCU. -- Radoslaw Skorupka Lodz, Poland ====================================================================== Jeśli nie jesteś adresatem tej wiadomości: - powiadom nas o tym w mailu zwrotnym (dziękujemy!), - usuń trwale tę wiadomość (i wszystkie kopie, które wydrukowałeś lub zapisałeś na dysku). Wiadomość ta może zawierać chronione prawem informacje, które może wykorzystać tylko adresat.Przypominamy, że każdy, kto rozpowszechnia (kopiuje, rozprowadza) tę wiadomość lub podejmuje podobne działania, narusza prawo i może podlegać karze. mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa,http://secure-web.cisco.com/1Lzj9zVRMTDFDNo4M7M8DN77CkXk2WwKjxggFK5bOAzJ9ymZvQtOryhCIWtwIGfzFgjCgGhx3jqsmmRUzK8UyoKVlWaloD7QWqqOTi3-85zptn8TXARBXIF6HMaBJR4m7Uj2iCFsfDrnhq8E3vBezbSn6n5PRnu5m389CcJs2szCnXQk34ulq1PlctcxfDqWatsHV6fDfS1b7TQR2Urdv6_rJKjsHo3ex15MuUxVQ993QvE15Fq6zrkheEgUpBUKMH0F8CkyGg5W3y41cnG3j60vFrbeXiSsdXeXqdyFZwNNyo8pwzg0gY5ZoYYZdFNwUHpDAfnC-6TZq8KqQIJURTQTaH4jiIyI1N68Reu6spyoeq-Zq9Xhnd7ZhLLGRaXeGsu5MoUVXGuL-bFONJ6InjaB4chOVGBWxt1XmpKbGHlb80NnvglwswCRfY4BR_m-T/http%3A%2F%2Fwww.mBank.pl, e-mail: kont...@mbank.pl. Sąd Rejonowy dla m. st. Warszawy XII Wydział Gospodarczy Krajowego Rejestru Sądowego, KRS 0000025237, NIP: 526-021-50-88. Kapitał zakładowy (opłacony w całości) według stanu na 01.01.2018 r. wynosi 169.248.488 złotych. If you are not the addressee of this message: - let us know by replying to this e-mail (thank you!), - delete this message permanently (including all the copies which you have printed out or saved). This message may contain legally protected information, which may be used exclusively by the addressee.Please be reminded that anyone who disseminates (copies, distributes) this message or takes any similar action, violates the law and may be penalised. mBank S.A. with its registered office in Warsaw, ul. Senatorska 18, 00-950 Warszawa,http://secure-web.cisco.com/1Lzj9zVRMTDFDNo4M7M8DN77CkXk2WwKjxggFK5bOAzJ9ymZvQtOryhCIWtwIGfzFgjCgGhx3jqsmmRUzK8UyoKVlWaloD7QWqqOTi3-85zptn8TXARBXIF6HMaBJR4m7Uj2iCFsfDrnhq8E3vBezbSn6n5PRnu5m389CcJs2szCnXQk34ulq1PlctcxfDqWatsHV6fDfS1b7TQR2Urdv6_rJKjsHo3ex15MuUxVQ993QvE15Fq6zrkheEgUpBUKMH0F8CkyGg5W3y41cnG3j60vFrbeXiSsdXeXqdyFZwNNyo8pwzg0gY5ZoYYZdFNwUHpDAfnC-6TZq8KqQIJURTQTaH4jiIyI1N68Reu6spyoeq-Zq9Xhnd7ZhLLGRaXeGsu5MoUVXGuL-bFONJ6InjaB4chOVGBWxt1XmpKbGHlb80NnvglwswCRfY4BR_m-T/http%3A%2F%2Fwww.mBank.pl, e-mail: kont...@mbank.pl. District Court for the Capital City of Warsaw, 12th Commercial Division of the National Court Register, KRS 0000025237, NIP: 526-021-50-88. Fully paid-up share capital amounting to PLN 169,248,488 as at 1 January 2018. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
