Seiko Instruments CM-2050C 20" Super VGA CRT Monitor 1024x768 4 BNC

Seiko Instruments CM-2050C 20" Super VGA CRT Monitor 1024x768 4 BNC Non-Interlaced

The Seiko Instruments CM-2050C is a 20-inch non-interlaced Super VGA CRT monitor designed for high-resolution workstation use. It supports a maximum resolution of 1024×768 and accepts both a standard HD-15 VGA signal input and four BNC connections (H/V sync, Blue, Green, Red), making it compatible with graphics workstations and computers that output separate RGB or composite sync signals. Sync on Green is supported, a common requirement for Unix and engineering workstations of the early 1990s. The CM-2050C is a multisync/multiscan design, meaning it automatically adapts to a range of horizontal and vertical sync frequencies rather than being locked to a single standard.

Specifications & What's Included

• Manufacturer: Seiko Instruments Inc. (SII)
• Model: CM-2050C (also referenced as CM-2050, CM2050)
• Type: CM-2050-10
• Screen size: 20" CRT, non-interlaced
• Maximum resolution: 1024 × 768
• Monitor type: Multisync / Multiscan
• Horizontal frequency: 31–50 kHz
• Vertical frequency: 50–90 Hz
• VGA frequency compatible: Yes
• VGA sync compatible: No (sync on green / composite sync required)
• Sync type: Sync on Green, Composite
• Video connectors: HD-15 (VGA SIGNAL) + 4 × BNC (H/V, B, G, R)
• Power: 100–120V AC, 2.7A, 50/60 Hz
• Country of manufacture: Japan
• Date code: 10-91 (October 1991)
• Certifications: UL Listed (E020444), CSA (LR98600)
• Front panel: Rotary adjustment knobs for image geometry and picture settings, power toggle
• Monitor only — no signal cables included

Applications

The CM-2050C dates from the early 1990s, the era when 20-inch CRT monitors represented the high end of professional display technology. Monitors of this type were used with Unix engineering workstations — Sun SPARCstations, SGI Indigo and Iris systems, HP 9000 workstations, DEC VAXstations, and IBM RISC System/6000 machines — many of which output RGB video over BNC rather than VGA, and commonly used sync-on-green signaling. The 4 BNC input with composite and sync-on-green support made monitors like the CM-2050C a standard fixture in CAD/CAM, scientific visualization, medical imaging, and publishing environments. Today these monitors are sought by vintage workstation collectors and hobbyists maintaining period-correct SGI, Sun, or HP workstation setups, as well as by retro computing enthusiasts who need a period-appropriate large CRT display with BNC connectivity.