| 摘要 |
<p>Storage protect keys are placed in a register in correlation to blocks of main storage. Initialization of a problem program is accompanied by selection of one of these registers via the high order bits of the first instruction to be executed. The key is stored in a separate store and thereafter compared against the key retrieved from the register addressed by the high order bits of each subsequent instruction. Failure to compare indicates a storage boundary has been crossed and an unauthorized instruction execution is being attempted.</p> |
