USI VM1230 12-Inch Monochrome Monitor Coax BNC RCA Security Commodore 64 117V

USI VM1230 12-Inch Monochrome Monitor Coax BNC RCA Security Commodore 64 117V

The USI (US International) VM1230 is a 12-inch monochrome CRT monitor designed for use with security and CCTV systems, the Commodore 64, and other composite video sources of the era. It accepts both BNC coaxial and RCA composite video inputs, with a rear BNC IN/OUT loop-through and a 75-ohm termination switch — a standard feature for daisy-chaining in security camera installations. A front-access panel covers eight analog adjustment controls for precise image tuning.

Specifications & What's Included

• Brand: USI (US International)
• Model: VM1230
• Display: 12-inch monochrome CRT
• Refresh rate: 75 Hz
• Power: AC 117V, 60Hz
• Video input 1: BNC coaxial with IN/OUT loop-through and 75-ohm termination switch
• Video input 2: RCA composite
• Rear switches: Picture/Data mode, Normal/Invert polarity, DC power jack
• Front controls (behind access door): H.Width, Focus, H.Hold, Bright, Contrast, V.Hold, V.Size, V.Lin
• Front panel: red power indicator LED, rocker power switch
• Dimensions: approximately 12 × 12 × 12 inches
• FCC Class B certified computing device
• Includes attached AC power cord

Applications

Monochrome composite video monitors like the VM1230 were widely used in the 1980s for two main purposes: as display terminals for early home and business computers, and as dedicated monitors in closed-circuit television (CCTV) and security camera systems. The BNC coaxial input with loop-through made it straightforward to wire into a multi-camera security setup, while the RCA input provided compatibility with consumer-standard composite video signals from computers such as the Commodore 64, which output standard composite video. The Normal/Invert and Picture/Data rear switches allowed the display polarity to be adjusted for different signal sources. Today these monitors are sought by vintage computing enthusiasts restoring Commodore 64 and similar 8-bit setups, by collectors of period computer hardware, and occasionally for use in legacy industrial or security applications that still rely on composite monochrome signals.