In computer history, the IBM PC/XT (introduced in the early 1980s) was the first IBM PC model to ship with a built-in hard disk drive rather than relying only on floppy disks. What was the storage capacity of that original internal hard disk (state the value in megabytes)?

Introduction / Context:
The question tests historical knowledge of personal computing hardware, specifically the storage capacity of the first hard disk drive bundled with IBM’s PC/XT model. Understanding this helps learners distinguish between floppy-disk capacities and early hard-disk capacities, a common area of confusion in computer history.

Given Data / Assumptions:

• Device in focus: IBM PC/XT (Extended Technology).
• Feature: It shipped with an internal hard disk drive as standard.
• Task: Identify the original drive’s capacity in megabytes (MB).

Concept / Approach:
We relate common storage media and their typical capacities from that era. 5.25-inch floppy disks commonly stored 360 KB (double-sided, double-density) or 1.2 MB (high-density, later), while 3.5-inch floppy disks stored 720 KB or 1.44 MB. Early PC hard drives for consumer machines were in the range of 5–20 MB, depending on model and year. The PC/XT’s standard shipped drive was the 10 MB ST-412-class drive.

Step-by-Step Solution:

Verification / Alternative check:
Cross-checking with standard PC timelines shows the IBM PC/XT (1983) shipped with a 10 MB hard disk (e.g., ST-412 class), while 20 MB drives became common shortly after in upgraded or later systems. This supports the 10 MB choice.

Why Other Options Are Wrong:

• 20 MB: More typical of later upgrades; not the standard original XT configuration.
• 1.44 MB: This is a common 3.5-inch floppy-disk capacity, not a hard disk capacity.
• 750 KB: Not a standard capacity for the PC/XT’s built-in drive and aligns with no common disk baseline of that time.

Common Pitfalls:
Learners often confuse floppy-disk capacities with hard-disk capacities or assume later upgraded configurations as the original default. Always match the capacity to the exact launch specification of the named model.

Final Answer:
10 MB