Automated Communication and System Mode Change
Original Publication Date: 1981-Nov-01
Included in the Prior Art Database: 2005-Feb-12
This technique enables the running of two microdiagnostic disks simultaneously. In the example described below, tHo disks are run to test a system's Attached Processor (AP) hardware. This technique uses a PUT register, a TAKE register, and two commands (VARY AP OFFLINE and VARY AP ONLINE) to control the operation of the two disks. The PUT register and TAKE register are used together to communicate between two diagnostic monitors. The two commands can vary the AP online and offline without leaving the microdiagnostic frame. The diagnostic monitors proceed as follows. 1. Load disk 1 on Port 3 (CPU) side and disk 2 on Port 7 (APU) side, and start both disks. 2. Disk 1 issues a TAKE and enters a wait state, waiting for a PUT from disk 2. Disk 2 runs its instruction execution and bus control function (IEF and BCF) tests. 3.