Sun Microsystems TOPS Flashcard MC 501-1631-01 Rev B ISA Network Card 1990

Sun Microsystems TOPS Flashcard MC 501-1631-01 Rev B ISA Network Card 1990

The TOPS Flashcard MC is a half-length ISA expansion card produced by TOPS, a Sun Microsystems company, in 1990. It provides network connectivity via a Mini-DIN 8-pin rear bracket connector and is built around the VLSI Technologies CHIPS chipset controller. The card carries FCC Class A compliance certification (ID 5356H) and was manufactured in the USA.

Specifications & What's Included

• Model: 501-1631-01 Rev B
• Product Line: TOPS — A Sun Microsystems Co.
• Bus Interface: ISA (Industry Standard Architecture), half-length
• Main Controller: VLSI Technologies CHIPS chipset
• Rear Bracket Connector: Mini-DIN 8-pin
• Form Factor: Half-length ISA card
• Year: 1990 (© 1990 per PCB silkscreen)
• Country of Manufacture: USA (FAR MADE IN U.S.A. per PCB)
• FCC ID: 5356H (FCC Class A compliant per PCB label)
• Notable ICs: Motorola SN74LS541N octal buffer (date code FFCP9011); multiple SMD logic ICs visible on component side
• Card only; no cables or accessories included

Applications

TOPS (The Open Protocol Standard) was a peer-to-peer networking system developed originally by Sun Microsystems that allowed DOS PCs, Macintosh computers, and Sun workstations to share files across a common network — notably AppleTalk/LocalTalk-based LANs. The Flashcard MC provided the ISA slot interface needed to connect DOS-based PCs into a TOPS network during the late 1980s and early 1990s, when cross-platform file sharing was far from trivial. The Mini-DIN 8-pin connector on the rear bracket is characteristic of LocalTalk wiring, reflecting TOPS' roots in Apple's cabling ecosystem. By the early-to-mid 1990s, Ethernet-based networking and TCP/IP largely displaced proprietary LAN solutions like TOPS, making cards of this type genuine vintage networking relics. Today these cards are sought by collectors of period Sun Microsystems and Apple networking hardware, as well as hobbyists maintaining legacy mixed-platform computing environments of that era.