DCA 007745 IRMA 3 Multiple Computer Interface ISA Card Rev D VC5832-0002

DCA 007745 IRMA 3 Multiple Computer Interface ISA Card Rev D VC5832-0002

The DCA 007745 is an ISA-bus expansion card from Digital Communications Associates (DCA), sold under the IRMA 3 (also written IRMA III) product line. It is a multiple computer interface card designed to allow a DOS-era IBM-compatible PC to connect simultaneously to IBM host environments and local area networks via its onboard coaxial and RJ-45 ports. The main controller is DCA's proprietary DIVINE ASIC (part number VC5832-0002), which manages protocol conversion and host communication. The board revision visible on this unit is Rev D.

Specifications & What's Included

• Manufacturer: DCA (Digital Communications Associates)
• Part Number: 007745
• Series: IRMA 3 / IRMA III
• Secondary Part Number: VC5832-0002 (controller ASIC designation)
• Hardware Revision: Rev D (per PCB label)
• Bus Interface: ISA — full-length card
• Main Controller: DCA DIVINE ASIC, VC5832-0002
• Memory: 4x Hyundai HY62064ALP-70 SRAM chips
• Crystal Oscillator: 37.7392 MHz
• Bracket Connectors: RJ-45 port and coaxial (BNC-style) port
• Internal Connector: Blue DB-style internal header on bracket edge
• Logic ICs: ST 74HC series and DCA-marked support ICs
• Switch Block: DIP switch bank for configuration (labeled on PCB)
• FCC Classification: Class A
• Designed in USA; U.S. Patent 4,885,482
• Included: Card only — no software, drivers, or documentation included

Applications

The DCA IRMA product line was a well-known family of IBM terminal emulation and host connectivity cards produced in the 1980s and early 1990s. IRMA cards allowed IBM-compatible PCs running MS-DOS or early Windows to connect to IBM mainframe and midrange host systems — including IBM 3270 and 5250 environments — by emulating the terminal hardware those systems expected. The IRMA 3 generation added support for multi-host or LAN connectivity, making a single PC card capable of connecting to coaxial-based IBM host links as well as twisted-pair (RJ-45) network segments. These cards were widely used in corporate and government computing environments where IBM host access from desktop PCs was required. They date from the late 1980s to early 1990s ISA-bus era, when full-length ISA cards of this type were standard in AT-class and 386/486-era PCs. Today they are sought by collectors of vintage PC hardware and by organizations maintaining legacy IBM host connectivity for older systems.