Browse Prior Art Database

Channel Simulator

IP.com Disclosure Number: IPCOM000047109D
Original Publication Date: 1983-Sep-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 3 page(s) / 68K

Publishing Venue

IBM

Related People

Dervin, JM: AUTHOR [+4]

Abstract

A channel simulator 100 (Fig. 1) is formed by reworking a network control unit (NCU) 50 containing a microprocessor and by adding a display terminal interface. Manufacturing facilities require some way for testing units 150 which will attach to channels, such as channel 15, of computer systems. It is too expensive to dedicate a computer system for performing such testing. The common practice is to build a channel simulator for testing the channel attached units 150. In Fig. 1, the channel simulator 100 receives program loads from host system 10 via NCU 50. This provides program flexibility to the channel simulator. In the past, these channel simulators were constructed using hardware for logic functions and, consequently, were physically large and costly.

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Channel Simulator

A channel simulator 100 (Fig. 1) is formed by reworking a network control unit (NCU) 50 containing a microprocessor and by adding a display terminal interface. Manufacturing facilities require some way for testing units 150 which will attach to channels, such as channel 15, of computer systems. It is too expensive to dedicate a computer system for performing such testing. The common practice is to build a channel simulator for testing the channel attached units 150. In Fig. 1, the channel simulator 100 receives program loads from host system 10 via NCU 50. This provides program flexibility to the channel simulator. In the past, these channel simulators were constructed using hardware for logic functions and, consequently, were physically large and costly. The present channel simulator incorporates a microprocessor and is particularly adapted to test network control units 50 attached to the channel 15 of host system 10. The network control unit 50, because it includes channel interface and driver/receiver hardware, can be modified and made into a channel simulator. The channel simulator 100 (Fig. 2) includes interface card 110 for interfacing with a display terminal, coax driver/receiver card 120, serializer/deserializer (SERDES) card 125, clock card 130, microprocessor 140, IBM System/370 interface card 150 and IBM System/370 driver/receiver card 160. Cards 120 and 125 function to receive program loads from host 10. Cards 150 and 160 are used to emulate the IBM System 360/370 channel function under microprogramming monitor and control. In order to simulate a 360/370 channel, it must be possible to drive the outbound bus and tag lines and receive the inbound bus and tag lines. This is accomplished in the following manner: The bus in lines normally driven by the NCU 50 are wired to the bus out lines of the bus interface cable. The bus out lines normally received by the NCU 50 are wired to the bus in lines of the bus interface cable. Similarly, on the tag interface cable, the in tags normally driven by the NCU 50, address in, status in, service in, operational in, and request in are wired to address out, command out, service out, suppress out, and hold out, respectively. The out tags normally received by the NCU, address out, command out, service out, and suppress out are wired to address in, status in, service in, and request in, respectively. In addition, the following changes had to be made to the channel interface and channel driver/receiver ca...