Trident TVGA8900D-R 512K 16-Bit ISA VGA DOS Video Card Rev B1 Union 7139 1994

Trident TVGA8900D-R 512K 16-Bit ISA VGA DOS Video Card Rev B1 Union 7139 1994

The Union 7139 is a 16-bit ISA VGA video card built around the Trident TVGA8900D-R graphics controller, a widely used chipset in IBM-compatible PCs of the early-to-mid 1990s. The card provides standard VGA output via a DB15 connector and carries 512KB of onboard video RAM, sufficient for standard VGA resolutions and color depths used throughout the DOS and early Windows era. The board revision is B1, confirmed by the PCB silkscreen, and the Trident chip is date-coded 1994.

Specifications & What's Included

• Chipset: Trident TVGA8900D-R (© Trident 1994, date code 9747)
• Bus Interface: 16-bit ISA
• Video Memory: 512KB DRAM
• Video Output: DB15 VGA connector on bracket
• Board: Union 7139, Revision B1
• Form Factor: Half-height ISA expansion card
• Compatible OS: DOS, Windows 3.x, Windows 95
• Card only — no drivers or accessories included

Applications

The Trident TVGA8900D-R was a mainstream ISA VGA controller produced in the early 1990s, common in budget and mid-range DOS/Windows 3.x machines from that era. Cards like this were found in 286, 386, and 486-class IBM-compatible desktop systems, providing reliable VGA output for business software, early graphical operating environments, and DOS games. Today the TVGA8900D-R is sought after for vintage PC restoration and retro computing builds — particularly for 486-era systems that require a 16-bit ISA video card with solid DOS compatibility and well-supported drivers. The 512KB framebuffer supports standard VGA (640×480 at 16 colors or 320×240 at 256 colors) as well as some SVGA modes at reduced color depth. Trident's TVGA line was one of the most widely cloned and OEM-supplied chipsets of the period, and drivers remain readily available for DOS, Windows 3.1, and Windows 95.