IBM 5280 Distributed Data System - Index of

,The main microprocessor 0 performs all of the non-I/O (input/output) operations,such as mathematical computations and data movement. The main microprocessor"I .. " ... " .... + .. ,,1 .. +h"" r1"""i,."" rni"rnnrncorrnrr IfJ thrnllnh ~01.;)\.1 ,",VIILIV'.J Lit\" U\.IW",,,,, .... " V,.,IV ......... ""'v.., ''''''''''''::tll ~The device microprocessors control all the operations for the attached devices. Themain microprocessor communicates with the device microprocessors via lOBs(input/output control blocks) in main storage m and hardware attention lines 0When the main microprocessor determines that work is required of a device microprocessor,it puts information into the appropriate lOB and activates an attentionline to the device microprocessor. When the device microprocessor detects theattention from the main microprocessor, it reads the lOB and performs the requestedwork. The storage access control iii directs access to main storage for all the microprocesso rs.AttentionLines\Diskette AttachmentMainStorage0StorageAccessControlII...,,\o', ..... 0 ...'/DisketteUnits(up to 4)Printer AttachmentI/'-------"-~To PrinterCommunications AttachmentLineAdapter• 38LS• DDSA• EIA.2