• 6502A (Original Apple III)
• 6502B (Later Apple III and Apple III Plus)

• Apple III: basic system, came with 128K RAM, ran Apple SOS 1.0. Original selling price was $4340 to $7800.
• Apple III revised: included 256K RAM, new sockets on motherboard, optional 5 MB ProFile drive. Sold for $3495.
• Apple III Plus: included 256K RAM, new logic board, working built-in clock, improved ports, easier card installation, ran Apple SOS 1.3. Sold for $2995.

• Port A: 9-Pin (DB-9) Joystick Input (can be used for Apple Silentype printer)
• Port B: 9-Pin (DB-9) Joystick Input
• Port C: 25-Pin (DB-25) RS-232-C Serial Interface
• 15-Pin NTSC-Compatible Color Video Port (can be used for RGB pure video)
• RCA Black and White Video Port
• Floppy drive port, up to 3 drives can be daisy chained
• 5-Volt Audio Port

• 280 x 192, black and white
• 280 x 192, 16 colors, foreground and background
• 140 x 192, full 16 colors
• 560 x 192, black and white

• 40 x 24, black and white, normal and inverse
• 80 x 24, black and white, normal and inverse
• 40 x 24, 16 colors, foreground and background
• All text modes have a software-definable 128-character set

• Shugart 143K 5.25-inch floppy drive

• 5.25-inch floppy drive, 5 MB ProFile Hard drive

• SOS (Sophisticated Operating System) versions 1.0 - 1.3, Apple DOS, CP/M (with Z-80 card)

• 74 keys (61 on main keyboard, 13 on numeric pad), full 128 character ASCII represented, all keys have automatic repeat except modifier keys, five modifier keys: SHIFT, CONTROL, ALPHA LOCK, and two program-definable "Apple" keys, four directional arrow keys with two-speed repeat, four other special keys: TAB, ESCAPE, RETURN, ENTER

Comments
The Apple III was meant to be a replacement for the venerable Apple II. Unfortunately, it suffered from a compromised design due in no small part to the Marketing Department's insistence that the III run Apple II software. The III could have been based on a more powerful, modern chip, but in order to emulate the II, Apple had to go with the antiquated 6502. It would have been prohibitively expensive to put two chips on the system board. The Apple III would be Apple's worst disaster to date and it nearly ruined the company. Many of the earliest Apple IIIs that shipped were returned because of hardware failure. The Apple III ran too hot and had no internal cooling fan. Its chips had the bad habit of popping out of their sockets. The III was eventually killed in favor of the IIe, which carried on the Apple II nameplate for the remainder of the 80s and kept Apple financially healthy.

Additional Apple III Information:

The Ill-Fated Apple III

Apple III Print Ads

DOS 3.3 and ProDOS Guide

Free Programs for the Apple II

Vectronic's Apple II Timeline

Apple Brings Computers to the Masses

Vectronic's Apple II Section