IBM 1 Series - Appendix A. General Purpose Interface Bus Adapter; Adapter Functional Description

Introduction
Appendix A. General Purpose Interface Bus Adapter (RPQ D02118)
The term “General Purpose Interface Bus (GPIB)” is commonly used to
identify the Institute of Electrical and Electronics Engineers (IEEE)
Standard 488, as approved in 1975 and updated in 1978 (IEEE Standard
488-1975, IEEE Standard 488-1978). This interface standard was
established to facilitate the interconnection of programmable
instrumentation and other system components.
The IBM Series/1 General Purpose Interface Bus Adapter Feature, RPQ
D02118, is designed to provide a cycle-stealing interconnection path
between the OEM devices that adhere to the IEEE Standard 488 and the
Series/1 processor I/O channel.
Adapter Functional Description
The GPIB adapter uses a bidirectional 16-signal interface for information
and data exchange. This signal interface may be grouped functionally into
three component buses (Figure A-1): (1) the management group (five
lines), which provides overall bus control; (2) the transfer group (three
lines), which provides an asynchronous three-wire “handshake” for
information exchange; and (3) the data group (eight lines), which transfers
all addressing, programming, and data information on the interface.
A normal GPIB implementation on the Series/1 consists of the GPIB
adapter, which acts as the bus controller, and up to 14 additional
noncontroller units. The controller first seizes the interface; it then
configures the network by designating a single device to transmit data
(talker) and a number of devices to receive data (listeners). The controller
may configure itself as a talker or a listener, and multiple listeners may be
active during any data or information transfer.
IBM Series/1
GPIB
adapter
I/O devices
(maximum of 14)
General interface management lines (5)
(3)
im Data byte transfer lines
QPanilel data tines OM
Figure A-1. Interface structure
General Purpose Interface Bus Adapter (RPQ D02118) A-1