IBM System/7 Functional Characteristics - All about the IBM 1130 ...

The absolute form can be obtained in the following manner.1. Invert by changing each position to its opposite binary value (from all l's to all0's in this example):1111 1111 1111 1111becomes0000 0000 0000 00002. Add 1 to the inverted number:0000 0000 0000 0000+10000 0000 0000 0001Negative results are always represented in twos-complement form, which specificallyexcludes a negative 0.STORAGE ADDRESSESFor processor module models A and B, storage capacity ranges from 2K (2,048) wordsto 16K (16,384) words. Storage between these limits can be obtained in 2K increments.For the model E, storage capacity ranges from 16K (16,384) words to 64K (65,536)words in increments of 4K. The address for any storage location in System/7 can becontained in a 16-bit word as in the following examples:Binary Address ( 16 bits) Hexadecimal Address Decimal Address0000 0000 0000 0000 0000 000000000 0111 1111 1111 07FF 2,0470001 0100 1010 0000 14A0 5,2800011 1111 1111 1111 3FFF 16,3830100 1110 0010 0000 4E20 20,0000111 1101 0000 0000 7D00 32,0001111 1111 1111 1110 FFFE 65,534REGISTERSStorage Address Register (SARIThe storage address register is a 16-bit register used by the processor to access eachlocation in main storage. Although the contents of this register cannot be controlleddirectly by the programmer, the console address lights indicate the contents of the SARduring the storage access machine cycle.IBM 5010 Processor Module 2-9