On 7/30/2017 9:57 PM, Charles Mills wrote:
Until the z13 (?), for example, NI, OI and XI were interruptible within a reference to a single byte. NI is actually fetch, AND, store. It could be interrupted between the fetch and the store. So two processors doing NI or OI on the same byte could get "logically impossible" results.
That changed waaay back with the z196... -- Edward E Jaffe Phoenix Software International, Inc 831 Parkview Drive North El Segundo, CA 90245 http://www.phoenixsoftware.com/
