Description
The Apple IIe (styled as Apple //e, or sometimes Apple ][e) is the
third model in the Apple II series of personal computers produced by
Apple Computer. The e in the name stands for enhanced, referring to the
fact that several popular features were now built-in that were only
available as upgrades and add-ons in earlier models. It also improved
upon expandability and added a few new features, which, all combined,
made it very attractive to first-time computer shoppers as a
general-purpose machine. The Apple IIe has the distinction of being the
longest-lived computer in Apple's history, having been manufactured and
sold for nearly 11 years with relatively few changes.
Although Apple hoped that 1984's Apple IIc would outsell the IIe, the
latter was more popular because of its slots.[8] 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 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, 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-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 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 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 //e" on its start up splash screen (as
opposed to the less-specific "Apple ][").
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 "//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 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 on November 15,
1993, officially retiring the entire Apple II family line with it.
Specifications
Instances
External links
Additional information
Apple //e repair guide
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[: Apple IIE Repair Guide :]
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Written By:
Double Density
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INTRODUCTION
------------
I bring this series to all of the Apple //E users who have experienced the
unfair and outrageous prices that repairmen of computers (especially at
Computerland) charge for their services, only to replace a $0.50 chip. I myself
have been charged $75 to have a $2.50 chip replaced, not to mention it took them
two weeks to get to my computer to replace the damn thing. At the end of this
series, most repairs on your computer you should be able to do on your own, and
most for less than the cost of a movie.
Before I get heavily into this discussion, may I make a small suggestion? Print
this out NOW! If you don't and your computer breaks down, then what are you
gonna do? Yup, you are gonna pay big bucks.
Open your computer and take a look at the motherboard. Looks confusing, eh? Not
really. The big black things are called integrated circuits, and these are what
break down or fail most often. The other things we will not worry about at the
moment.
Up and down the left side of the motherboard you will see letters A-F, and along
the bottom the numbers 1-14. This is the way Apple locates their chips on the
board - much like a city map with grids. Here are the names, and locations, and
the approximate costs for each of the chips on the board. Don't let the names of
the chips scare you or anything on this chart. It is mainly for information, and
you won't need to know anything about the chips on the board (aside from the
fact they are broken, which will come later).
IC # Location Approximate $ Description Notes
-------------------------------------------------------------------------------
74LS02 B8 0.78 Quad 2-input NOR
74S10 C5 0.78 Triple 3-input NAND
74S109 C1 1.34 Dual JK Flip-flop
74LS125 E1 1.12 Tri-state quad buffer
74LS138 B5 1.22 Expandable 3/8 Encoder
74LS154 C10 2.80 4-16 decoder/multiplexer
74LS166 F5 1.84 8-bit serial in,
parallel out shift register
74LS244 B1,B3 2.80 Tri-State octal line driver
74LS245 B2 1.70 Tri-State octal bus receiver
74LS251 C11 1.55 Tri-State 8-input multiplexer
74LS374 D3 1.98 Tri-State octal-D flip-flop
NE558 A12 2.00 Quad 555 timer
MC741 A11 0.75 Operational Amplifier
ULN2003 Analog Card ???? 7-channel input (from Apple)
driver
LM3146 Analog Card ???? Transistor Array (from Apple)
MC3470 Analog Card ???? Floppy disk (from Apple)
read amplifier
MC3764 F6-F13 20.00 64k x 1 bit RAM
6502B B4 14.00 8 bit microprocessor
KB ROM D12 8.00 Keyboard ROM
VID ROM F4 12.00 Video ROM
CD ROM D10 20.00 Applesoft ROM
EF ROM D8 20.00 Monitor ROM
HAL D1 56.00 Programmed Array (from Apple)
logic
IOU D6 56.00 I/O unit (from Apple)
MMU D4 56.00 Memory Mgmt Unit (from Apple)
AY3600 D14 16.00 Keyboard Decoder
Ok, that's all of the chips on the motherboard, and a few from the Analog card,
that is the one inside your disk drive (apple drives only). If you need to order
one of these chips from Radio Shack or some other local electronics store, then
you ask for the chips by the number in the left hand column. For example, if
your paddles were not working and the cables were good, you would need to start
with the NE558 chip, and that is what you order. More about that later, though.
Don't worry about the big costs of the ROM chips or the CPU. Most computer
breakdowns are of the 74LSxxxx series and you will most normally have to deal
with those only.
Now, before you go poking around your motherboard popping out chips and sticking
them back in, a few tips and reminders to keep your apple running right, and how
not to screw anything up...
1) Never touch ANYTHING in or on your computer, including your disk drives,
before grounding yourself on something. Static electricity, especially in
the wintertime can reach as high as 10,000 volts - enough to fry any of the
delicate chips inside your computer.
2) Buy a chip puller. They are cheap, and you will save your fingers from
getting pins from the chips stuck in them, and blood all over everything.
3) Always note the orientation of the chip you pull out, so that you can put
the new chip in the same way. There is a notch in one end of the chip, or a
dot at one end. Either way, be sure the new chip has the notch or dot in the
same place as the old one.
4) Use power strips and surge protectors. The surge protector for obvious
reasons, and the power strip for preventing wear and tear on the switches.
5) Keep your coke off the keyboard. Liquids can blow every chip they touch.
6) Take special care about static electricity when messing around with the CPU,
the ROM chips, the MMU and the IOU chips. These are quite sensitive to
static charges.
7) Don't open your monitor. This is stupid, xrays and 30kV's are running around
inside and if you don't know what you are doing, you will have radiation
damage, or worse yet, your parent will smile when they collect life
insurance on you.
8) Don't pull cards out or put cards in when the power is on. You will kill
either the card or the computer, I promise.
9) Check everything outside of the computer before you start fiddling around
inside. Usually cables, switches or other shit like that are the cause of
the problem.
Now: I am dividing up this series into 5 parts as follows:
1) Start-Up Problems
2) Run Problems
3) Display Problems
4) Keyboard Problems
5) Other I/O Problems
And I will release them as I type them. Don't hold your breath, as I am in
school and hardly have lots of time...
Part I - Start-Up Problems
--------------------------
This section covers all problems that occur at the time you turn the power on,
or at start up, including no power, no boot up, no beep and no display...
1) No power light, no beep, drive won't run:
Probable defect: 1) 74LS125 at E1 is bad (replace and test)
2) 74S109 at C1 is bad (replace and test)
3) 74S02 at B8 is bad (replace and test)
2) Power light on, no message, no beep:
Probable defect: 1) 74S02 at B8 is bad (replace and test)
2) 74S109 at C1 is bad (replace and test)
3) Power light on, message, no beep:
Probable defect: 1) (experts only) PAL 16R8/8323T at D1 is bad
4) System won't boot, power light on, drive won't run, garbage on screen:
Probable defect: 1) Bad EF ROM at E10 (replace and test)
2) Bad 6502B at C4 (replace and test)
5) System won't boot, power light on, message on screen, drive won't boot:
Probable defect: 1) Clean connector pins
2) Clean or replace ribbon cable
3) Bad ULN2003 on analog card (replace and test)
4) Bad regulator on analog card (replace card)
6) System won't boot, everything on, drive keeps running:
Probable defect: 1) Reseat disk, check disk, check cable, reseat
card. (coming later if this doesn't work)
7) System won't boot, disk drive runs and then stops:
Probable defect: 1) Bad DOS
2) Bad Disk
3) Bad RAM chip on motherboard (f6-14) replace
and test
8) System boots and then stops, no display:
Probable defect: 1) Video cable bad (replace and test)
2) Video connector bad (replace)
3) Brightness knob on monitor?
4) 74LS02 at B8 bad (replace and test)
5) 74LS10 at C5 bad ("""""""""""""""")
6) 74LS166 at F5 bad (replace and test)
7) 74LS374 at D3 bad (replace and test)
8) IOU at E5 bad (replace and test)
9) 2732 ROM at F4 bad (replace and test)
If you need advance help, you can reach me at my board by chat or by mail. If you have questions or suggestions, also call my board.
Part II - Run Problems
----------------------
1) Disk drive will not read (I/O error or disk just runs on and on)
Probable Defect: Remedy:
---------------- -------
a) Bad Disk Replace Disk
b) Wrong DOS Try another disk
c) Disk not seated Reseat disk
d) Read head not reading Replace head
e) Cable loose or bad Reseat or replace cable
f) Bad chip on analog card Replace Analog Card
2) Disk drive will not write (read is OK)
Probable Defect: Remedy:
---------------- -------
a) Write protected Remove tab
b) Protect switch bad Replace switch
c) Disk not formatted format disk
d) Cable bad or loose Check/Replace cable
e) Corroded connectors Clean connectors
f) Bad 74LS125 replace (analog card)
g) Bad CA3146 replace " "
h) Bad MC3470 replace " "
i) Bad ULN2003 replace " "
j) Bad Write head replace
k) head alignment off realign head
3) Disk reads or writes occasionally
Probable Defect: Remedy:
---------------- -------
a) Cable corrosion clean connector pins
b) Connector corrosion clean connector pins
c) noise interference good luck
d) disk tracking off realign head
4) Occasionally keyboard locks up and computer locks up
Probable Defect: Remedy:
---------------- -------
a) Program error debug program
b) no keyboard out put coming later
c) bad RAM chip replace and test
d) bad MMU chip replace and test
e) bad CPU at C4 replace and test
Part III - Display Problems
---------------------------
1) No Display - Screen all White
Probable Defect: Remedy:
---------------- -------
a) shift register latch-up replace 74LS166 at F5 and test
b) ROM data hung up replace 2732 character ROM (F4)
2) No Display - No Video
Probable Defect: Remedy:
---------------- -------
a) Bad Cable Replace and test
b) low signal adjust brightness
c) Bad monitor test monitor
d) Bad 74LS02 at E8 replace and test
e) Bad 2N3906 at A14 replace and test
f) Bad 2N3904 at A14 replace and test
g) Bad 74LS10 at C5 replace and test
h) Bad 74LS166 at F5 replace and test
i) Bad 2732 ROM at F4 replace and test
j) Bad 74LS374 at D3 replace and test
k) Bad IOU at E5 replace and test
l) Bad PAL 16R8 at D1 replace and test
3) No Display - Screen Black
Probable Defect: Remedy:
---------------- -------
a) Brightness bad Adjust
b) Bad monitor test monitor
c) Bad IOU at E5 replace and test
d) Bad 2732 ROM at F4 replace and test
4) No Color
Probable Defect: Remedy:
---------------- -------
a) Bad IOU at E5 replace and test
b) Capacitor C32 shorted replace (soldering required)
c) Inductor L3 Bad replace (soldering required)
5) No Syncronization
Probable Defect: Remedy:
---------------- -------
a) Bad IOU at E5 replace and test
b) Bad monitor replace or repair
6) Bad cursor or no cursor
Probable Defect: Remedy:
---------------- -------
a) Bad EF ROM at E10 replace and test
b) Bad 2732 ROM at F4 replace and test
7) Bad inverse or flash
Probable Defect: Remedy:
---------------- -------
a) Bad 2732 ROM at F4 replace and test
8) No text
Probable Defect: Remedy:
---------------- -------
a) Bad 2732 ROM at F4 Replace and test
b) Bad IOU ROM at E5 Replace and test
9) Video - Bad color
Probable Defect: Remedy:
---------------- -------
a) Bad HAL at D1 Replace and test
10) Bad Graphics (lo and Hi bad); text ok
Probable Defect: Remedy:
---------------- -------
a) Bad IOU at E5 Replace and test
11) Bad Graphics (HI), low and text ok
Probable Defect: Remedy:
--------------- -------
a) Bad IOU at E5 replace and test
Part IV - Keyboard Problems
---------------------------
1) Bad key action - some keys or no keys work
Probable Defect: Remedy:
---------------- -------
a) Bad Key replace key
b) Bad or loose cable check and replace cable
c) Bad AY3600 at E14 replace and test
d) Bad 2716 ROM at E12 replace and test
2) Bad key action - prints wrong characters
Probable Defect: Remedy:
---------------- -------
a) Bad 2716 ROM at E12 replace and test
b) Bad AY3600 at E14 replace and test
3) Bad key action - unwanted repeat
Probable Defect: Remedy:
---------------- -------
a) Bad AY3600 at E14 replace and test
b) Bad capacitor C71 replace (soldering required)
4) Repeat key won't work
Probable Defect: Remedy:
---------------- -------
a) Bad Key replace and test
b) Bad AY3600 at E14 replace and test
c) Bad Capacitor C70 replace (soldering required)
5) Key top pops off
Well, just glue that fucker back on or get a new keyboard.
Part V - Other input/output problems
------------------------------------
1) Speaker - volume too low
Probable Cause: Remedy:
--------------- -------
a) transistor Q5 marginal replace (soldering required)
2) Speaker - won't click
Probable Cause: Remedy:
--------------- -------
a) Bad speaker Replace speaker
b) speaker wires bad or loose check or replace
c) Bad transistor (Q5) replace (soldering)
d) Bad IOU at E5 replace and test
3) Cassette - can't load data
Probable Cause: Remedy:
--------------- -------
a) Bad cable Replace and test
b) Volume not set pproperly Retry at different volume
c) No signal on tape Replace tape
d) Bad LM741 at A11 Replace and test
e) Bad 74LS251 at C12 Replace and test
f) Bad 74LS154 at C10 Replace and test
4) Cassette - Can't write data
Probable Cause: Remedy:
--------------- -------
a) No signal to tape reconnect or replace cable
b) Tape bad replace tape
c) Bad IOU at E5 replace and test
5) Game paddle - does not work at all
Probable Cause: Remedy:
--------------- -------
a) Bad cable Replace
b) Bad 558 timer at A12 Replace and test
c) Bad 74LS251 at C12 Replace and test
d) Bad 74LS154 at C10 Replace and test
6) Game paddle button won't work
Probable Cause: Remedy:
--------------- -------
a) Button bad Replace button
b) Broken wire Replace wire
7) Game Paddle - knob does not work correctly
Probable Cause: Remedy:
--------------- -------
a) Bad pot in paddle Replace pot
b) Broken wire in cable Replace wire
8) Card in peripheral slot does not work
Probable Cause: Remedy:
--------------- -------
a) Bad 74LS138 at B5 replace and test
b) Bad 74LS154 at C10 replace and test
c) Bad 74LS10 at C5 replace and test
Additional hints:
-----------------
Look and smell and feel the chips in your computer for things that seem to be
bad or out of place. Feel for hot spots, smell for blown capacitors, etc etc.
Notice anything out of the ordinary and replace it if it doesn't look, smell or
feel right. You can search for heat-blown chips by cooling each chip one at a
time with freon from a can and examining the results on the operation of your
computer. I f you find a chip that allows the computer to work cold, but when it
warms up, p hooey, replace it. If all fails, take it to Computerland. Their
prices are unreasonable, but i f you couldn't fix it from what I typed, you can
be sure that you are going to g et your money's worth from them as they try to
track down the problem, and cry t he whole way.
Files
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Photographs
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Descriptions provided by Every Mac and/or Low End Mac | Contacts: afberendsen AT gmail DOT com |
