On legacy IBM-compatible systems, a POST error code in the 6xx range typically indicates a problem with which device class?

Introduction / Context:
Power-On Self-Test (POST) codes help technicians quickly narrow down failing subsystems. Classic IBM/PC-compatible BIOS families commonly used broad numeric ranges associated with device classes. Recognizing these ranges speeds diagnosis without digging through every setting.

Given Data / Assumptions:

• Legacy BIOS conventions where 6xx codes relate to diskette (floppy) subsystems.
• Examples include codes such as 601 indicating a diskette drive or controller error.
• Other device classes (keyboard, hard disk) typically occupy different ranges (e.g., 301 keyboard).

Concept / Approach:
POST code families are mapped to hardware groups. In many legacy references, 6xx errors point to the diskette drive, cable, or controller problems. While exact codes can vary by BIOS vendor, technicians historically learned these common associations for fast triage before consulting the specific service manual.

Step-by-Step Solution:

Verification / Alternative check:
Cross-reference the BIOS vendor’s POST table for exact meanings (e.g., 601 Diskette Drive Error). Replacing or reseating the floppy cable commonly resolves intermittent 6xx errors.

Why Other Options Are Wrong:

• Hard drive: Typically 17xx, 1xx, or vendor-specific codes.
• Keyboard: Often 301/302, outside the 6xx family.
• CD-ROM: ATAPI/IDE optical issues rarely report as 6xx in classic BIOS tables.
• All of the above: Overly broad and not aligned with classic code ranges.

Common Pitfalls:
Assuming all BIOSes share identical codes; always verify with the exact system manual after using the range as a quick hint.

Final Answer:
Floppy drive