MacWorld has a look back at how the original Mac came to life. From the Apple II (in 1977), through the Apple III, the Lisa and finally the Apple Mac the story covers it all!
The original Mac featured a 9-inch black-and-white display, 3.5-inch floppy drive (which could store 400KB of data on each disk), 128KB of RAM and a Motorola 68000 processor running at 8 MHz. It shipped with MacWrite, a word processing tool, and MacPaint, a drawing tool. Later the same year, Apple shipped the Mac 512K, which doubled the installed RAM but kept the same design.
Read more here: In the beginning: The making of the Mac | Macworld