Following the release of the original Macintosh (a.k.a. Macintosh 128K) in 1984, the Macintosh 512K in 1985, and the Macintosh Plus in 1986, in 1987, Apple released the Macintosh SE. Several versions of this computer were released. Let’s discuss this computer in detail.

The Macintosh SE was based on the same processor (Motorola 68000), had the same size, and used the same screen size and resolution (9-inch black-and-white with 512 x 342 pixels) as the previous Macintosh models (except the Macintosh SE/30, which used a Motorola 68030 processor). It inherited the external SCSI port, the 800 KB floppy disk drive (later upgraded to a 1.44 MB floppy, as we will discuss), and 1 MB of RAM using four SIMM-30 memory modules (allowing you to upgrade the memory to 4 MB) from the Macintosh Plus.

This computer, however, came with new features. The most important was the addition of an internal hard disk drive (20 MB or 40 MB) connected to a new internal SCSI port. This was the first Macintosh computer to feature an internal hard drive. (The dual drive model didn’t come with an internal hard drive.)

Another difference between the Macintosh SE and the previous models was the addition of a new bus for connection of peripherals such as keyboard and mouse, called ADB (Apple Desktop Bus).

The Macintosh SE was also the first Mac to feature an expansion slot, called the PDS (Processor Direct Slot). In fact, “SE” stands for “System Expansion.” Actually, the Macintosh II, which was released at the same time, also featured expansion slots. The Macintosh II was a full-sized desktop computer, unlike the SE and its predecessors, which were compact computers.

Another feature that was added with the SE was a cooling fan. Previous Apple computers didn’t feature a fan because Steve Jobs thought it was noisy and “inelegant.”

In Figure 1, you can see a Macintosh SE system with a keyboard and a mouse.

Macintosh SE TutorialFigure 1: The Macintosh SE

Nowadays, the first thing you will notice when looking at the Macintosh SE is how small it was. In Figure 2, we compare the Macintosh Plus to a 21-inch LCD monitor.

Macintosh SE TutorialFigure 2: The Macintosh SE compared to a 21-inch LCD monitor

Unlike the previous models, the computer didn’t come with a keyboard; you had to buy one separately. At the time, two choices were available: the Apple Keyboard (model M0116), which was cheaper and thus more common (the one shown in Figures 1, 2, and 3) and the Apple Extended Keyboard (model M0115), which was bigger and more expensive. We show this keyboard in Figure 4. Since the Macintosh SE used an ADB port, any keyboard based on this connection could be used. For example, you could use the Apple IIgs keyboard or buy a keyboard manufactured by a different company.

Macintosh SE TutorialFigure 3: Apple Keyboard (M0116)

Macintosh SE TutorialFigure 4: Apple Extended Keyboard

The mouse that came with the Macintosh SE was different from the one that came with the previous Macintosh models, as you can see in Figure 5 (models A9M0331 or G5431). As with the keyboard, you could use any mouse based on the ADB connection.

Macintosh SE TutorialFigure 5: The mouse

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.