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The Apple IIe lowered production costs and improved reliability by merging the function of several off-the-shelf ICs into single custom chips, reducing total chip count to 31 (previous models used 120 chips). The IIe also switched to using newer single-voltage 64x1 DRAM chips instead of the triple-voltage 16x1 DRAM in the II/II+. 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]]. Also added was a backport-accessible DE-9 joystick connector, making it far easier for users to add and remove game and input devices (previous models requiring plugging the joystick/paddles directly into a 16-pin DIP socket on the motherboard; the IIe retained this connector for backwards compatibility). Also improved were port openings for expansion cards. Rather than cutout V-shaped slot openings as in the Apple II and II Plus, the IIe has a variety of different-sized openings, with thumb-screw holes, to accommodate mounting interface cards with DB-xx and DE-xx connectors (removable plastic covers filled the cutouts if not used).
Although the lower IC count and greater use of cooler-running CMOS components improved reliability over previous Apple II models, Apple still retained the practice of socketing all ICs so that servicing and replacement could be performed more easily. Later-production IIe models had the RAM soldered to the system board rather than socketed. This proved important as quite a few IIes shipped with Micron-branded 64kx1 RAM chips that had significant reliability issues.
Despite the hardware changes, the IIe maintained a high degree of backwards compatibility with the previous models, allowing most hardware and software from those systems to be used. Apple provided technical information on the IIe to hundreds of developers before its release, and claimed that, as a result, 85 to 90% of Apple II software worked with it.<ref name="shea19830207">{{cite news | url=https://books.google.com/books?id=_y8EAAAAMBAJ&pg=PA1 | title=Apple IIe runs 90% of software designed for II | work=InfoWorld | date=1983-02-07 | access-date=1 February 2015 | author=Shea, Tom | pages=1 | archive-date=March 10, 2023 | archive-url=https://web.archive.org/web/20230310064441/https://books.google.com/books?id=_y8EAAAAMBAJ&pg=PA1 | url-status=live }}</ref>
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In March 1985, the company replaced the original machine with a new revision called the Enhanced IIe. 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 purpose of the update was to make the Apple IIe more compatible with the Apple IIc (released the previous year) and, to a smaller degree, the Apple II Plus. This change involved a new processor, the CMOS-based [[WDC 65C02|65C02]] CPU, a new character ROM for the text modes, and two new ROM firmware chips. The 65C02 added more CPU instructions, the new character ROM added 32 special "[[MouseText]]" characters (which allowed the creation of a [[Graphical user interface|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 [[Apple II Mini-Assembler|Mini-Assembler]]—which had vanished with the introduction of the II Plus firmware).
===Platinum IIe===
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