Dell 980 service manual Drives, External Connectors

Mini-tower	one full-height card
Desktop	without riser card— one low-profile card
	with riser card— one full-height card
Small form factor	one low-profile card
PCI Express x1
Mini-tower	one wireless card
Desktop	one wireless card
Small form factor	one wireless card

Drives

Externally accessible - 5.25-inch drive bay(s)

Mini-tower	two bays
Desktop	one bay
Small form factor	one slimline bay
Externally accessible - 3.5-inch drive bay (s)
Mini-tower	one bay
Desktop	one bay
Small form factor	one bay

Internally accessible - 3.5 inch drive bay(s) for hard drives

Mini-tower	two bays
Desktop	one bay
Small form factor	one bay

NOTE: Your computer can support up to two 2.5 inch hard drives with brackets.

External Connectors
Audio
Back panel	two connectors for line-in/ microphone
	and line-out
Front panel	two front-panel connectors for
	headphones and microphone
eSATA	one 7-pin connector
Network	one RJ45 connector
Parallel	one 25-pin connector (bidirectional)
Serial	one 9-pin connector; 16550C-compatible
USB - Front panel
Mini-tower	four connectors
Desktop	two connectors
Small form factor	two connectors
USB - Back panel
Mini-tower	six connectors
Desktop	six connectors
Small form factor	six connectors