IBM 5280 Distributed Data System - Index of

Addressing a Binary RegisterEach binary register begins on a 2-byte boundary from hexadecirnal 0100 to 01 FE(relative to the beginning of the partition). In a source program, a binary register isspecified by a register number or a label, which is converted to a 16-bit address inthe object code. All 16-bit addresses for binary registers begin with 01, as thefollowing chart shows:BR62 is stored at location hex 017C.~.Hex 0 :2 4 6 8 A Cc E010 0 1 2 3 4 5 ~ 7011 8 9 10 11 12 13 14 15012 16 17 18 19 20 21 2~ 23013 24 25 26 27 28 29 3p 31014 32 33 34 35 36 37 38 39015 40 41 42 43 44 45 ~ 47•~ 48 49 50 51 52 53 54 55(017 .~ --6T 1-68 ~59 r-69 r-61· f-~2" 630i8 64 65 66 67 68 69 70 71019 72 73 74 75 76 77 78 7901A 80 81 82 83 84 85 86 87018 88 89 90 91 92 93 94 9501C 96 97 98 99 100 101 102 103010 104 105 106 107 108 109 110 11101E 112 113 114 115 116 117 118 11901F 120 121 122 123 124 125 126 127Following is an alternative method to convert a binary register number (using BR62as an example) to a 16-bit address:1. Multiply the register number by 2: 62 x 2 = 1242. Convert the result to hexadecimal: decimal 124 = hexadecimal 007C3. Add hexadecimal 0100: 007C + 0100 = 017CIf a binary double register is referred to in a source instruction, the address in theobject code is the address of the rightmost register.134