Expansion Cards

As previously mentioned, one of the new features of the Macintosh SE was its expansion connector, called PDS (Processor Direct Slot). This expansion connector allowed you to install expansion cards, such as accelerator and networking cards. Accelerator cards replaced the 68000 microprocessor with another more powerful CPU, usually a 68020, and frequently added more RAM, allowing you to have more than 4 MB.

The Macintosh Portable, the Macintosh SE/30, and the Macintosh IIfx also had a PDS connector. Although the PDS connector of the Macintosh Portable had the same number of contacts as the PDS slot of the Macintosh SE, it was not compatible with the connector available on the Macintosh SE. The Macintosh SE/30 and the Macintosh IIfx used a different model of the PDS connector, called PDS 68030, which was not compatible with the PDS connector available on the Macintosh SE.

Macintosh SE TutorialFigure 23: The PDS 68000 connector of the Macintosh SE

To install an expansion card, you had to open the computer and remove the motherboard – a rather complicated process.

In Figure 24, you can see a Radius SE accelerator card installed on the Macintosh SE motherboard, which replaced the 68000 microprocessor with a 68020. In Figure 25, we show a different accelerator card that was available for the Macintosh SE, the Prodigy SE from Levco, which also replaced the microprocessor with a 68020 model and added 16 MB of RAM.

Macintosh SE TutorialFigure 24: Radius SE accelerator card installed

Macintosh SE TutorialFigure 25: Levco Prodigy SE accelerator card with 16 MB of RAM

In Figures 26 and 27, you can see two different models of Ethernet cards.

Macintosh SE TutorialFigure 26: Ethernet card

Macintosh SE TutorialFigure 27: Another Ethernet card

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.