DCA MacIRMA 003088 Rev A NuBus 3270 Mainframe Emulation I/O Card for Mac

DCA MacIRMA 003088 Rev A NuBus 3270 Mainframe Emulation I/O Card for Mac

The DCA MacIRMA 003088 is a NuBus expansion card that enables IBM 3270 mainframe terminal emulation on Apple Macintosh computers equipped with NuBus slots. Manufactured by DCA (Digital Communications Associates), it gives a Mac host the ability to connect directly to IBM SNA mainframe environments, appearing as a 3270 terminal to the host system. The Rev A designation is confirmed by the silkscreen label on the PCB.

Specifications & What's Included

• Manufacturer: DCA (Digital Communications Associates)
• Product Name: MacIRMA
• Part Number: 003088
• Revision: Rev A
• Bus Interface: NuBus (Apple Macintosh NuBus slot)
• Emulation: IBM 3270 mainframe terminal emulation
• Protocol: IBM SNA / 3270 data stream
• Bracket Connector 1: BNC coaxial (coax connection to 3270 controller)
• Bracket Connector 2: RJ-45 (token ring or twisted-pair network connection)
• NuBus Edge Connector: Panduit 100-096-053 (visible on card)
• PCB population: multiple DIP ICs, PLCC chips, and discrete components visible
• Form Factor: NuBus card (full-length)
• Included: card only

Applications

The MacIRMA line was DCA's flagship product for bridging Apple Macintosh computers into IBM mainframe and midrange SNA networks during the late 1980s and early 1990s. At the time, large enterprises ran IBM mainframe systems -- the IBM 3090, 3080, and 4300 series -- accessed through 3270 cluster controllers such as the IBM 3174 and 3274. The MacIRMA card allowed a NuBus-equipped Mac (the Mac II family: Mac IIx, IIcx, IIci, IIfx, Quadra 700/900/950) to connect directly to those controllers via coaxial or token ring cabling, running DCA's IRMA terminal emulation software. This let users access mainframe applications, perform file transfer using IND$FILE, and share printers on the SNA network -- all from the Mac desktop. This is a legacy product specific to the NuBus Mac era; it is of interest today primarily to vintage Macintosh collectors, historians, and IT professionals maintaining legacy IBM SNA infrastructure or Mac II systems.