Dell OptiPlex 990 (Early 2011) - Manual (Page 86)

Drives
3.5–inch SATA drive bays
Mini-Tower two
Desktop one
Small Form Factor one
Ultra Small Form Factor none
2.5–inch SATA drive bays
Mini-Tower two
Desktop one
Small Form Factor one
Ultra Small Form Factor one
External Connectors
Audio:
Back Panel two connectors for line-out and line-in/
microphone
Front Panel two connectors for microphone and
headphone
Network Adapter one RJ45 connector
Serial one 9-pin connector; 16550C compatible
Parallel one 25-pin connector (optional for mini-
tower)
USB 2.0
Mini-Tower, Desktop, Small Form
Factor Front Panel: 4
Back Panel: 6
Ultra Small Form Factor Front Panel: 2
Back Panel: 5
Video 15-pin VGA connector, 20-pin DisplayPort
connector
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