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Initial Program Load Card for Computer Systems

IP.com Disclosure Number: IPCOM000073725D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Greene, WB: AUTHOR

Abstract

The IBM Systems 1130 and 1800 utilize different IPL procedures which currently require separate loaders for each system. The purpose of the initial Program Load (IPL) card is to provide a single IPL card for both systems. This card will be particularly useful with systems which may be either 1130 or 1800 based.

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Initial Program Load Card for Computer Systems

The IBM Systems 1130 and 1800 utilize different IPL procedures which currently require separate loaders for each system. The purpose of the initial Program Load (IPL) card is to provide a single IPL card for both systems. This card will be particularly useful with systems which may be either 1130 or 1800 based.

The 1130 IPL procedure forms 80 words in core storage of addresses B through 79. Each card column forms one 16-bit computer word. Card rows 12 through 2 form the op code (bits 0 through 4). Bits 5 through 7 of the computer word are left blank. Card row 3 is placed in bits 8 and 9 and card rows 4 through 9 become bits 10 through 15 to finish the word. As a consequence, no input/output control commands (IOCC) can be loaded with the IPL on the 1130 but must be built with the available instructions. Following IPL, control is transferred to the instruction at address 0.

IPL on the 1800 uses two card columns to form one 16-bit computer word. Card rows 12 through 5 of column 2 become bits 0 through 7 of the computer word and card rows 12 through 5 of column 1 become bits 8 through 51. Thus, 40 words are loaded from one 80 column card and are located at core addresses 0 through 39. Card rows 6 through 9 are not used. Following IPL, control is transferred to the instruction at address 0.

To develop a single IPL card, card columns 1 and 2 have been arranged so that on the 1130, a shift right accumulator is performed fol...