Introduced in October 1990, the Classic came with 1MB of RAM, a SuperDrive, and space to mount an internal SCSI hard drive. RAM expansion was via a 1MB daughter card with two open slots, which could accept a pair of 256KB or 1MB SIMMs.
A new feature on the Classic was elimination of the brightness knob. Instead brightness was controlled with the Brightness control panel. A peculiar feature was the ability to boot from ROM by holding control-option-X-O at startup.
The Classic was the last Mac to use an 8MHz 68000 CPU.