Editing Apple IIe (section)

==Revisions==
In production from January 1983 to November 1993, the Apple IIe remained relatively unchanged through the years. However, there was one significant motherboard update, a major firmware update and two cosmetically revised machines. These revisions are detailed below.

===Revision A motherboard===
At the time of the Apple IIe's introduction, and well into the first few months of production, this motherboard shipped with all units. [[Apple II graphics|Graphics modes supported]] are identical to, and limited to, those of the Apple II Plus before it (Double-Low/Double-High resolution is not supported). This revision logic board is also  incompatible with a small number of newer plug-in expansion slot cards. Under a free service upgrade program, Apple advised owners of the revision A to have authorized dealers replace it with the revision B motherboard.

===Revision B motherboard===
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 order to support this, some modifications had to be made to the motherboard, which became the Revision B. 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.

Apple upgraded the motherboard free of charge. In later years Apple labeled newer IIe motherboards with a "-A" suffix once again, although in terms of functionality they were Revision B motherboards.

===New case and keyboard===
In 1984, Apple revised the case and keyboard. 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 [[electromagnetic interference|radio frequency interference]]. The new case is made of dyed plastic mold in a slightly darker beige with a simplified snap-case lid. The other noticeable change is a new keyboard, with more-professional-looking print on darker keycaps (small black lettering, versus large white print). This was the first cosmetic change.

===Enhanced IIe===
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).

Although it affected compatibility with a small number of software titles (particularly those that did not follow Apple programming guidelines and rules, used [[illegal opcode]]s 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&nbsp;— mostly productivity applications and utilities&nbsp;— 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. An Enhanced machine identifies itself with the name "Apple //e" on its start-up splash screen (as opposed to the less-specific "Apple ][").

===Platinum IIe===
[[Image:Apple Platinum IIe.jpg|thumb|right|The Platinum Apple IIe with numeric keypad]]

In January 1987 came the final revision of the Apple IIe, often referred to as the Platinum IIe, due to the color change of its case to the light-grey color scheme that Apple dubbed "Platinum". Changes to this revision were mostly cosmetic to modernize the look of the machine. Besides the color change, there was a new keyboard layout with built-in numeric keypad. The keyboard was changed to match the layout of the [[Apple IIGS]], with the reset key moved above the ESC and '1' keys, the Open and Solid Apple modifier keys replaced by [[Command key|Command]] and Option and the power LED relocated above the numeric keypad. Gone were the recessed metal ID badges (showing the Apple logo and name, with "//e" beside it) replaced with a simpler "Apple IIe" silk screened on the case lid in the Apple [[Garamond]] font. A smaller Apple logo badge remained, which was moved to the right side of the case.

Internally, a (reduced in size) Extended 80-Column Card was factory-installed, making the Platinum IIe come standard with 128&nbsp;KB RAM and Double-Hi-Res graphics enabled. The motherboard has a reduced chip count by merging the two system ROM chips into one and using higher-density memory chips so its 64&nbsp;KB RAM can be made up of two (64 Kbx4) chips rather than eight (64 Kbx1) chips, bringing the count down to a total of 24 chips. 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 [[capacitor]]s were added. While this made no difference to the average user, it had the negative effect of lowering the available [[Bandwidth (computing)|bandwidth]] to the socket, which is often used by specialized devices for such purposes as measuring temperature, controlling a robotic device, or even simplistic networking for data transfer to another computer. In such cases, the specialized devices were rendered useless on the Platinum IIe unless the user removed the capacitors from the board.

There were no firmware changes present, and functionally the motherboard was otherwise identical to the Enhanced IIe.  This final model of the Apple IIe (which was not sold in Europe) was quietly discontinued on November 15, 1993, which (following the discontinuation of the Apple II<small>GS</small> a year earlier) effectively marked the end of the Apple II family line.