It is the first Apple II with built-in lowercase and 80-column text support, as well as 64K RAM, while reducing the total chip count from previous models by approximately 75%.

[4] In September 1981 InfoWorld reported—below the PC's announcement—that Apple was secretly developing three new computers "to be ready for release within a year": Lisa, Macintosh, and "Diana".

Describing the last as a software-compatible Apple II replacement—"A 6502 machine using custom LSI" and a simpler motherboard—it said that Diana "was ready for release months ago" but decided to improve the design to better compete with the Xerox 820.

"Now it appears that when Diana is ready for release, it will offer features and a price that will make the Apple II uncompetitive", the magazine wrote.

For this reason the motherboard design is much cleaner and runs cooler as well, with enough room to add a pin-connector for an (optional) external numeric keypad.

[8] InfoWorld's reviewers, Apple II Plus owners for four years, wished that the IIe's price were lower but stated that it "does give you more for your money, however".

The magazine also chose the IIe as the best educational computer above $1000, citing Apple's strong early commitment to the market and large number of third-party education-related peripherals.

Shortly after the "Revision A" motherboard's release in 1983, engineers discovered that the bank-switching feature (which used a paralleled 64 KB of RAM on the Extended 80-Column Card or 1 KB to produce 80 columns using bank-switching) could also be used to produce a new graphics mode, Double-High-Resolution, which doubles the horizontal resolution and increases the number of colors from the 6 of standard High-Resolution to 16.

In addition to supporting Double-High-Resolution and a rarely used Double-Low-Resolution mode (see specifications above) it also added a special video signal accessible in slot 7.

The original IIe uses a case very similar to the Apple II Plus, painted and with Velcro-type clips to secure the lid with a strip of metal mesh along the edge to eliminate radio frequency interference.

It is completely identical to the previous machine except for four chips changed on the motherboard (and a small "Enhanced" or "65C02" sticker placed over the keyboard power indicator).

The 65C02 added more CPU instructions, the new character ROM added 32 special "MouseText" characters (which allowed the creation of a GUI-like display in text mode, similar to IBM code page 437), and the new ROM firmware fixed problems and speed issues with 80-column text, introduced the ability to use lowercase in Applesoft BASIC and Monitor, and contained some other smaller improvements (and fixes) in the latter two (including the return of the Mini-Assembler—which had vanished with the introduction of the II Plus firmware).

Although it affected compatibility with a small number of software titles (particularly those that did not follow Apple programming guidelines and rules, used illegal opcodes that were no longer available in the new CMOS-based CPU, or used the alternate 80-column character set that MouseText now occupied) a fair bit of newer software — mostly productivity applications and utilities — required the Enhanced chipset to run at all.

An official upgrade kit, consisting of the four replacement chips and an "Enhanced" sticker badge, was made available for purchase to owners of the original Apple IIe.

An alternative at the time, which some users chose as a cost-cutting measure, was to simply purchase their own 65C02 CPU and create (unlicensed and illegal) duplicates of the updated ROMs using re-rewritable EPROM chips.

When Apple phased out the Enhancement kit in the early 1990s, this became the only available method for users looking to upgrade their IIe, and remains so right up until the present day.

Internally, a (reduced in size) Extended 80-Column Card was factory-installed, making the Platinum IIe come standard with 128 KB RAM and Double-Hi-Res graphics enabled.

A solder pad location on the motherboard, present since the original IIe, for (optionally) making presses of the "Shift" keys detectable in software, is now shorted by default so that the feature is always active.

Next, in a move to reduce radio frequency interference when a joystick plugs into the motherboard's game I/O socket, filtering capacitors were added.

The Gemini duplicates most of the functions of a standard Apple IIe, minus RAM, ROM, video generation and CPU.

Many of the built-in Macintosh peripherals can be "borrowed" by the card when in Apple II mode (i.e. extra RAM, 31⁄2-inch floppy, AppleTalk networking, clock, hard disk).

As video is emulated using Macintosh QuickDraw routines, it is sometimes unable to keep up with the speed of a real Apple IIe, especially in the case of slower host machines.

To support this, special double-capacity video and keyboard ROMs are used; in early motherboards they had to reside on a tiny circuit card that plugged into the socket.

During approximately the same time period that the Platinum IIe was being produced (1987), Apple released an alternative machine for the European market.