GPIB bus width: Determine the number of dedicated data lines carried by the IEEE-488 (GPIB) bus for parallel data transfer.

Introduction / Context:
The IEEE-488 General Purpose Interface Bus (GPIB) is a parallel instrument bus widely used in test and measurement. Understanding its signal lines is foundational for system integration.

Given Data / Assumptions:

• GPIB provides distinct groups of lines: data lines, handshake lines, management/control lines, and ground/returns.
• Only the number of data lines is asked, not the total wire count.
• Data lines are used to carry a byte at a time in parallel.

Concept / Approach:
GPIB moves data in 8-bit bytes over dedicated parallel conductors. Separate handshake lines (DAV, NRFD, NDAC) coordinate transfer timing, allowing heterogeneous device speeds.

Step-by-Step Solution:
Identify the data group: DIO1 through DIO8.Recognize that handshake and management lines are separate and not counted as data lines.Conclude that there are 8 data lines.

Verification / Alternative check:
Pinout references label the parallel data lines as DIO1–DIO8, confirming an 8-bit data path.

Why Other Options Are Wrong:
1 or 4 would indicate serial or nibble-width, which GPIB is not. 16 would imply a wider bus than the standard defines for data. 9 is incorrect; the ninth relevant signals are handshake/control, not data.

Common Pitfalls:
Confusing total conductor count (including control/handshake/grounds) with the data path width.

Final Answer:
8