In 1979 Software Arts introduced the first computer spreadsheet, Visicalc for the Apple II. The boards included floppy disk controllers, SCSI cards, video cards, and CP/M or PASCAL emulator cards. These allowed hobbyists to add additional cards made by Apple and many other vendors who quickly sprung up. Among the Apple II's most important features were its 8 expansion slots on the motherboard. External storage was originally on cassette tape, but later Apple introduced an external floppy disk drive. It included a BASIC interpreter and could support graphics and a color monitor. It came with 4 KB RAM, but could be extended up to 48 KB RAM. The Apple II used a MOS 6502 chip for its central processing unit. The Apple II started the boom in personal computer sales in the late 1970s, and pushed Apple into the lead among personal computer makers.
Wozniak and Jobs demonstrated a prototype in December, and then introduced it to the public in April 1977. By August of that year, Wozniak started designing an improved version, the Apple II. In 1976, computer pioneers Steve Wozniak and Steve Jobs began selling their Apple I computer in kit form to computer stores.
