Apple IIe Enhanced
 | |
| Apple IIe Enhanced | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Home computer |
| Released | March 1985 |
| Discontinued | December 1986, superseded by the Platinum IIe |
| CPU | 65C02 @ 1.023 MHz (Apple part 338-6503) |
| Memory | 64 KB RAM on the main board, 128 KB with an extended 80-column card; 16 KB ROM |
| Storage | Cassette; Disk II 5.25-inch floppy; 3.5-inch UniDisk with a Liron card; hard disk via a controller card |
| Display | 40×24 and 80×24 text; 280×192 high-resolution; 560×192 double high-resolution on a suitable board |
| Sound | 1-bit speaker toggled at $C030 |
| OS / Firmware | Apple DOS 3.3, ProDOS, CP/M with a Z-80 card |
| Predecessor | Apple IIe |
| Successor | Apple IIe Platinum |
The Apple IIe Enhanced is the Apple IIe with a four-chip change, introduced in March 1985 and made until December 1986, when the Platinum IIe replaced it.[1] There is no new motherboard: the machine is an Apple IIe whose processor, two Monitor ROMs and character generator ROM have been changed.
What the upgrade actually is
[edit | edit source]Apple sold the change as a dealer-fitted kit, and the dealer document is explicit about what comes out and what goes in.[2]
| Position | Removed | Fitted |
|---|---|---|
| Microprocessor | 6502, 370-6502 | 65C02, 338-6503 |
| Monitor ROM (CD) | 342-0135 | 342-0304 |
| Monitor ROM (EF) | 342-0134 | 342-0303 |
| Character generator ROM | 342-0133 | 342-0265 (U.S.) |
Only the character generator ROM differs by country. Apple lists 342-0273 (United Kingdom), 342-0274 (French), 342-0275 (German), 342-0276 (Italian), 342-0306 (Western French) and 342-0307 (Western Spanish); the two Monitor ROMs and the processor are the same for U.S. and European machines.[2]
Note that Apple's own document calls the part simply a 65C02 and identifies it by Apple part number 338-6503. It does not name a manufacturer, and machines are found with 65C02s from more than one second source, so a page or a listing that insists on one particular maker is asserting more than Apple did.
Fitting it
[edit | edit source]Apple's procedure, in Apple's order:[2]
- Turn off the power switch but leave the computer plugged in.
- Remove the cover and check that the small red light inside the case is off.
- Touch the power supply case to discharge any static on you.
- Locate the four chips; you may need to remove interface cards to reach them.
- Rock each chip out gently, a little at a time from each end. Apple's warning: "It is very easy to accidentally pull up the socket along with the 6502."
- Embed the old chips in the antistatic foam the new ones came in, and label them.
- The notch on each new chip faces the keyboard. Align all pins before pressing down.
The kit also contained the "Enhanced" sticker for the power light.[1]
What changed in the firmware
[edit | edit source]The new Monitor ROMs fixed most of the known problems in the IIe's 80-column firmware. The old routines disabled interrupts for too long for the developers of the day, and Applesoft did not work properly with them.[1] The Enhanced ROMs:[1]
- allow Applesoft and Monitor commands to be entered in lower case
- restore the mini-assembler, absent since Integer BASIC, entered with "!" from the Monitor rather than by jumping to an address
- add direct entry of ASCII characters into memory, and an "S" command that searches memory for a byte sequence
- improve interrupt handling
- make GET, HTAB, TAB, SPC and comma tabbing work properly in 80-column mode
The Monitor's "L" disassembly command still does not decode the new 65C02 opcodes, although the Apple IIc disassembler does.[1]
The new character generator ROM adds MouseText, the 32 box-drawing and interface characters first seen on the IIc. They occupy the codes previously used for flashing characters in 80-column mode, which is why some older programs display MouseText where they used to display inverse upper case.[1][2] That is a consequence of the upgrade, not a fault in the machine or the chip.
Appearance
[edit | edit source]Machines sold new as Enhanced IIes have darker keycaps, smaller key legends printed in black and moved to the upper part of the key, and the word "Enhanced" added to the power light.[1] A machine upgraded in the field has the sticker but the original keycaps.
Double high-resolution graphics
[edit | edit source]An enhanced machine is not automatically a double high-resolution machine. The four-chip change does not include the board modifications that Revision B introduced for double high-resolution, so an original Revision A board given the Enhanced chip set may still be unable to produce it.[1] Check the board revision before looking for a fault elsewhere.
Power supply
[edit | edit source]Unchanged from the Apple IIe: +5 V ±3%, +11.8 V ±6%, −5.2 V ±10%, −12 V ±10%, 60 W continuous and 80 W intermittent, maximum case temperature 55 °C.[3] The shift-key hazard described on Apple IIe applies unchanged.
Buying and identification
[edit | edit source]- The four Apple part numbers above are the reliable identification. A machine with 342-0303 and 342-0304 fitted is enhanced whatever the sticker says, and a machine with the sticker and 342-0134/342-0135 fitted is not.[2]
- Enhancement kits and loose 65C02s are still traded, and mislabelled or remarked processors do turn up. Compare against Apple's part number rather than a maker's logo.
Things that are not faults
[edit | edit source]- Older software showing MouseText characters in place of inverse upper case is the documented consequence of the new character generator ROM[2]
- The Monitor disassembler not decoding 65C02 opcodes is how the Enhanced ROMs were shipped[1]
- No double high-resolution on an early Revision A board is a board limitation, not a failure[1]
Gallery
[edit | edit source]-
Apple IIe Enhanced (front view) -
Enhanced IIe keyboard and "Enhanced" power light -
Inside, showing the replaced 65C02 and ROM sockets -
MouseText characters
See also
[edit | edit source]References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 Steven Weyhrich, Apple II History, Chapter 7, "The Apple IIe", apple2history.org. The Enhanced IIe of March 1985 and its four-chip upgrade kit; the firmware changes (80-column fixes, lower-case entry, the returning mini-assembler, the ASCII entry and memory search commands, improved interrupt handling, the Applesoft 80-column fixes); the cosmetic changes to the keyboard and the "Enhanced" power-light sticker; the MouseText display problem in older programs; the Revision A and Revision B boards and the note that an enhanced Revision A board is not necessarily capable of double high-resolution graphics; the model timeline.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Apple IIe Enhancement Kit: Dealer's Installation Instructions, Apple Computer, Inc., part number 030-1142-B - hosted on this wiki as File:Apple IIe Enhancement Kit Dealer Installation Instructions.pdf. Table 1 and Figures 1 and 2: the four chips replaced and their part numbers before and after, the U.S. (NTSC) and European (PAL) board positions, the country-specific character generator ROMs, and the installation procedure including the warning about pulling the socket up with the 6502.
- ↑ Apple II Reference Manual - For //e Only, Apple Computer, Inc., 1982 (Apple part 030-0357-B) - hosted on this wiki as File:Apple IIe Reference Manual 1982.pdf. Table 7-2, power supply specifications; the supply's self-protection conditions; the single-wire shift-key modification at X6 and the hand-control short-circuit warning.