Browse Prior Art Database

Program Testing Technique

IP.com Disclosure Number: IPCOM000080906D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Reigel, FA: AUTHOR

Abstract

All instructions in a program are rapidly tested without changing any branch condition hardware. The program may be stored in any writable memory.

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Program Testing Technique

All instructions in a program are rapidly tested without changing any branch condition hardware. The program may be stored in any writable memory.

A record is made of all memory addresses used by program instructions, and sets of desired branch conditions are chosen to together account for all program addresses. The branch instructions are then modified for the first set of conditions chosen, and the program is executed. Additional program runs are performed for each additional set, after changing the branch instructions to the appropriate conditions. Finally, the branch instructions are restored to normal.

In a typical application of this technique, cards are initially punched representing the address expected to be used. These cards are then compared to the addresses actually used during testing and the variance is printed. Additional cards may be initially prepared to indicate the desired sets of branch conditions. Depending on the computer used, these may change a branch on n=8 either to an unconditional branch to n=8 (by replacing the branch condition "8" in the instruction with "15") or to an unconditional branch to n not= R (by placing branch condition "0" in the instruction).

In the drawing, all addresses 25-31 and 110-111 are tested during two sequential test runs. Prior to the first run, the conditional branch instructions at addresses 26 and 28 are replaced by the set A of branch instructions. Addresses 25-28 and 31 are then t...