US Robotics Sportster 28800 V.34 Fax Modem ISA Card 00084000 V.42bis PC

US Robotics Sportster 28800 V.34 Fax Modem ISA Card 00084000 V.42bis PC

The US Robotics Sportster 28800 (model 00084000) is an internal ISA bus dial-up fax modem card for IBM PC-compatible desktop computers. It operates at up to 28,800 bps under the V.34 standard, with V.42bis data compression and V.42 error correction. The card connects to a standard telephone line via an RJ-11 TELCO jack and includes a second RJ-11 PHONE pass-through port on the bracket. An onboard speaker provides dial and connection audio feedback.

Specifications & What's Included

• Manufacturer: US Robotics
• Model: Sportster 28800
• Part Number: 00084000
• Bus Interface: ISA (Industry Standard Architecture)
• Form Factor: Half-length ISA card
• Maximum Data Rate: 28,800 bps (V.34)
• Data Compression: V.42bis
• Error Correction: V.42
• Fax: Yes
• Main Controller: US Robotics DSP (USR proprietary DSP chip, visible on PCB)
• Secondary Controller: NEC USA chip (visible on PCB)
• Connectors: RJ-11 TELCO (line in), RJ-11 PHONE (pass-through)
• DIP switch bank: 8-position (positions 1–8 visible on bracket)
• Onboard speaker for call-progress audio
• FCC Registration: CJ6/USA-E5828-FA-E
• Industry Canada: 550 5967 A
• Copyright date on PCB: 1994
• Card only — no cables, driver disks, or accessories included

Applications

The US Robotics Sportster line was one of the most widely deployed internal modem families of the mid-1990s, a period when V.34 at 28.8 Kbps represented the practical ceiling for consumer dial-up speeds before V.90 and 56K modems arrived in the late 1990s. ISA internal modems like this one were standard equipment in IBM PC/AT-compatible desktops running MS-DOS, Windows 3.x, and early Windows 95 systems. They were used for dial-up BBS access, early internet connections via ISPs, fax transmission, and remote access applications. The US Robotics Sportster cards were particularly popular in small business and home office settings and are well-regarded for driver compatibility and solid V.34 performance. Today these cards are sought after for retro PC builds, vintage computing restorations, and period-correct ISA-slot desktop systems from the Pentium and 486 era. Installation requires a free ISA slot; the card is not compatible with PCI, PCIe, or modern motherboards that lack ISA slots.