I just looked up "External Interruption" in the Principles. There are at least 9 possible causes.
IIRC on the System 360 there was an eight-pin Molex connector available and a customer-provided box of some sort could trigger an external interrupt by pulling the appropriate pin to ground. See page 19 of http://www.bitsavers.org/pdf/ibm/360/systemSummary/GA22-6810-12_360sysSumJan74.pdf . IIRC MICR check sorters used this feature to generate their high-priority interrupts to the processor. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Tom Brennan Sent: Saturday, October 19, 2019 7:24 PM To: [email protected] Subject: Re: Best way for a task to give up the CPU and let other tasks run? Interesting, thanks! So it generates an external interrupt. I always thought that one was only for the external interrupt "key", but this page indicates CPU timer and some kind of CP-to-CP communication too: https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zconcepts/zconc_interrupts.htm Ok... now back to my weekend work, like changing the oil in my truck. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
