IBM 2250 Programming
"The IBM 2250 Display Unit Model 3 is a cathode-ray tube (CRT) display console which can be attached to a System/360 via the IBM 2840 Display Control Model 2."This is information extracted from: IBM System/360 Component Description
IBM 2250 Display Unit Model 3
IBM 3840 Display Control Unit Model 2
A27-2721-0, 1967
http://www.bitsavers.org/pdf/ibm/2250/A27_2721-0_2250mod3Descr.pdfNote that the 2250-4 (1130 attached) had a significantly different set of mode orders than those described here.http://www.bitsavers.org/pdf/ibm/2250/A27-2723-0_2250mod4Descr.pdf
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