Apple //e (enhanced) - MAME machine

Computer published 41 years ago:

Apple IIe © 1983 Apple Computer Co.

TECHNICAL
Microprocessor:

• 6502 or 65C02 running at 1.023 MHz
• 8-bit data bus

Memory:

• 64 KB RAM built-in
• 16 KB ROM built-in
• Expandable from 64 KB up to 1 MB RAM or more

Video modes:

• 40 and 80 columns text, white-on-black, with 24 lines¹
• Low-Resolution: 40×48 (15 colors)
• High-Resolution: 280×192 (6 colors)²
• Double-Low-Resolution: 80×48 (15 colors)
• Double-High-Resolution: 560×192 (15 colors)²

¹ Text can be mixed with graphic modes, replacing either bottom 8 or 32 lines of graphics with four lines of text, depending on video mode
² effectively 140×192 in color, due to pixel placement restrictions

Audio:

• Built-in speaker; 1-bit toggling
• Built-in cassette recorder interface; 1-bit toggle output, 1-bit zero-crossing input

Expansion:

• Seven Apple II Bus slots (50-pin card-edge)
• Auxiliary slot (60-pin card-edge)

Internal connectors:

• Game I/O socket (16-pin DIP)
• RF modulation output (4-pin Molex)
• Numeric keypad (11-pin Molex)

External connectors:

• NTSC composite video output (RCA connector)
• Cassette in/out (two 1?8-inch mono phono jacks)
• Joystick (DE-9)

TRIVIA
Apple had planned to retire the Apple II series after the introduction of the Apple III in 1980; after that machine turned out to be a disastrous failure, management decided the further continuation of the Apple II was in the company's best interest. So after three and a half years at a stand-still, came the introduction of a new Apple II model — the Apple IIe (codenamed Diana and Super II). The Apple IIe was released in January 1983, the successor to the "Apple II Plus". Some of the hardware and software features of the Apple III were borrowed in the design of the Apple IIe. The culmination of these changes led to increased sales and greater market share of both home and small business use.

One of the most notable improvements of the Apple IIe is the addition of a full ASCII character set and keyboard. The most important addition is the ability to input and display lower-case letters. Other keyboard improvements include four-way directional cursor control and standard editing keys (Delete and Tab), two special Apple modifier keys (Open and Solid Apple), and a safe off-to-side relocation of the Reset key. The auto-repeat function (any key held down to repeat same character continuously) is now automatic, no longer requiring the REPT key (now gone) found on the previous model's keyboard.

The machine came standard with 64 KB RAM, with the equivalent of a built-in Apple Language Card in its circuitry, and had a new special Auxiliary slot (replacing slot-0, though electronically mapped to slot-3 for compatibility with earlier third-party 80-column cards) for adding more memory via bank-switching RAM cards. Through this slot it also includes built-in support for an 80-column text display on monitors (with the addition of a plug-in 1 K memory card, via bank-switching of 40 columns) and could be easily doubled to 128 KB RAM by alternatively plugging in an Apple's Extended 80 Columns Card. As time progressed, even more memory could be added through third party cards using the same bank-switching slot, or alternatively general purpose slot cards that addressed memory 1 byte at a time (i.e. Slinky RAM cards). A new ROM diagnostic routine could be invoked to test the motherboard for faults and its main bank of memory.

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). 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). The Apple IIe maintains a high degree of backwards compatibility with the previous two Apple II models, allowing most hardware and software from those systems to be used.

The Apple IIe was used by several rock bands for album and music video graphics. Yes used an Apple IIe to create the cover of their 90125 album. Fishbone created their self-titled debut EP logo on an Apple IIe. The Residents used one to create the graphics on their Mole Show home video release, as well as the It's a Man's Man's Man's World music video. The Brazilian pop/rock band Biquini Cavadão used an Apple IIe clone (a Sperctrum ED) to generate a count down clock that appears in a video clip of the band.

UPDATES
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, two cosmetically revised machines and an official compatibility solution from Apple, in the form of an LC PDS card for certain models of the Macintosh computer line, known as the Apple IIe Card. These revisions are detailed below.

• The 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. Graphics modes supported are identical, and limited to, that of the Apple II Plus before it. The logic board is not compatible with the ROM based firmware update (introduced some years later) and most newer plug in expansion slot cards.
• The 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 Columns Card; or 1 KB to produce 80 columns using bank-switching) could also be used to produce a new graphics mode, Double-High-Resolution, with doubles the horizontal resolution and increases the number of colors from the 6 of standard High-Resolution to 15. 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 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 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 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.
• The Enhanced IIe: In March 1985, Apple replaced the original machine with a new revision called the Enhanced IIe. It is completely identical to the previous machine except for 4 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 in some respects to a smaller degree, the "Apple II Plus". This change involved a new processor, the CMOS based 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 GUI-like display in text mode, similar to IBM code page 437), and the new ROM firmware fixed problems and speed issues with 80 columns 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 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 Enhancement chipset to run at all. An official upgrade kit, consisting of these 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 choose 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 present day. An Enhanced machine identifies itself with the name Apple IIe on its start up splash screen (as opposed to the less specific Apple II).

• The Platinum IIe: 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 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 IIe 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 Columns Card was factory pre-installed, making it come standard with 128 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 used higher density memory chips so its 64 KB RAM could 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 capacitors were added. While this made no difference to the average user, it had the negative effect of lowering the available 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 is otherwise identical to the Enhanced IIe. This final model of the Apple IIe was discontinued in November 15, 1993; officially retiring the entire Apple II family line with it.

• International versions: The Apple IIe keyboard differed depending on what region of the world it was sold in. Sometimes the differences were very minor, such as extra local language characters and symbols printed on certain keycaps (e.g. French accented characters on Canadian IIe, or the British Pound symbol on the UK IIe) while other times the layout and shape of keys greatly differed (e.g. European IIe). In order to access the local character set and keyboard layout, a user-accessible switch is found on the underside of the keyboard — flipping it will instantly switch the video output and keyboard input from the US character set to the local set. 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. In some countries these localized IIe's also support 50 Hz PAL video instead of the standard 60 Hz NTSC video and the different 220/240 volt power of that region. An equivalent of the "PAL color card" for the earlier Apple II europlus model was integrated into the motherboard of these IIes, so that color graphics are available without the addition of a slot card.

Another difference with the European IIe, is the Auxiliary slot physically moved in location so it is in line and in front of slot-3, preventing both slots from being used simultaneously for full-sized cards. A few third-party cards are affected by this: some European cards plug into both slots simultaneously and are thus unusable on American IIes, and some American cards that do not fit into the case of European IIes because the European location of the Auxiliary slot leaves less room for them.

CONTRIBUTE
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