Processor:
Motorola 68000, 8 MHz, with an 8 MHz system bus and a 16-bit data path
RAM: The SE came with 1 MB of RAM as standard, and is expandable to 4 MB. The logic board has four 30-pin SIMM slots; memory must be installed in pairs and must be 150 ns or faster.
Video: The built-in 512 × 342 monochrome screen uses 21,888 bytes of main memory as video memory.
Storage: The SE can accommodate either one or two floppy drives, or a floppy drive and a hard drive above. After-market brackets were available to allow the SE to accommodate two floppy drives as well as a vertically oriented hard drive above them; however, this was not a configuration supported by Apple. In addition, an
external floppy disk drive may also be connected, making the SE the only Macintosh besides the
Macintosh Portable which could support three floppy drives, though its increased storage, RAM capacity and optional internal hard drive rendered external drives less of a necessity than for its predecessors. The hard disks were 20 and later 40 MB
SCSI units that featured an activity LED visible from the front. Such indicators were customary on PCs of the era, while the SE was the first Macintosh ever to have one.
Battery: A 3.6 V 1/2AA lithium battery, which must be present in order for basic settings to persist between power cycles, is located on the logic board. Macintosh SE machines which have sat for a long time have experienced
battery corrosion and leakage, resulting in a damaged case and logic board. Some SE models feature a board-mounted battery holder, while others have the battery soldered directly in place.
Expansion: A
Processor Direct Slot on the logic board allows for expansion cards, such as accelerators, to be installed. The SE can be upgraded to 50 MHz and more than 5 MB with the
MicroMac accelerators. In the past other accelerators were also available such as the Sonnet Allegro. Since installing a card required opening the computer's case and exposing the user to high voltages from the internal
CRT, Apple recommended that only authorized Apple dealers install the cards; the case was sealed with then-uncommon
Torx screws.
Upgrades: After Apple introduced the
Macintosh SE/30 in January 1989, a logic board upgrade was sold by Apple dealers for US$1,699 as a high-cost upgrade for the SE, consisting of a new SE/30 motherboard, case front and internal chassis to accommodate the upgrade components.
ROM/Easter egg: The SE ROM size increased from 64 KB in the original Mac (and 128 KB in the Mac Plus) to 256 KB, which allowed the development team to include an
Easter Egg hidden in the ROMs. By jumping to address 0x41D89A (or reading from the ROM chips), it is possible to display four images of the engineering team. == Models ==