FAQ (Frequently Asked Questions) about Macintosh Duo's

  * Last Revision: 04/18/94 *

In October of 1992 Apple released an entirely new kind of computer,
the Macintosh Duo.  The Duo, being such a strange beast, has left a
lot of people in confusion.  This file summarizes the Duo
information I've collected to date - hopefully it will end some of
the confusion.  This information is accurate as of today to the
best of my knowledge, but I make no warranties.  I'd appreciate any
corrections or updated information being mailed to me (please be
succinct and patient about a response).

I post updated versions of this FAQ on comp.sys.mac.portables roughly 
every two weeks and copies are available via anonymous FTP at 
mac.archive.umich.edu and it's mirrors in the archive/mac/util/powerbook 

                                         Nicholas C. De Mello
Added since last post

o New Virus: INIT 29-B.  A variation on an old bug, this
   was spotted in California two weeks ago, and (while not
   malignant) is virulent.  It spreads fast and can cause
   problems.  Disinfectant 3.5 is on all the standard sites
   (sumex-aim.stanford.edu, mac.archive.umich.edu, etc)

o The 040 Duo's will be released May 16th, along with the
   second generation full Duo Dock.

o The 603 Duo will be released January of 1995.

o Upgrades to LC040 logic boards and active color displays
   are offered for all Duo's, at $1000 and $2000.

o Express modem software 1.5 is out there, but a lot of folks
   are reporting problems.  You might want to wait a while
   before upgrading.

Next project

Trying to make a 'section 4' that will have portable 
information that's not unique to the Duo.  Ie ram and 
battery info, airlines x-rays, battery friendly word 
processors.  Hopefully, this'll eventually grow into
a seperate FAQ.

Table of Contents

Part 1: The Duo

 * Introduction: What is a Duo?

 * The Models: What Duo models are/will be available?

    Duo 210  : Economy Duo
    Duo 230  : Standard Duo
    Duo 250  : Active Matrix Duo
    Duo 270c : Color Duo
    Duo 280  : 040 Gray Duo   -- May 16, 1994
    Duo 280c : 040 Color Duo
    Duo 290  : 603 Gray Duo
    Duo 290c : 603 Color Duo  -- January, 1995
 * Dockless Duos: Do I have to buy a Dock?

    File Transfers
    Ram Disks
    Updating Systems
    Installing Software

 * Optimizing Duos: How can I squeeze the most out of my Duo?

       Why don't my title bars have that "3-D" affect?
       Why doesn't Strech 3.0 work with my Duo?
       How can I get that "3-D" affect in my title bars?
       What is a FPU?
       Do *I* need/want one?
       How does a FPU affect battery life?
       What's ram?
       How much ram do I need?
    RAM Disks
       What is a ram disk?
       Why/when should I use a ram disk?
       How do I install a RAM system disk?
       How do I get rid of a RAM disk (get the ram back)?
       What's that switch on the battery for?
       What do the numbers on my battery mean?
       What's a "type II" battery?
       Which battery do I have?
       Can I use the new (type II) batteries in my 210/230?
       Do I need to completely discharge (condition) my batteries?
       What's the *right* way to insert a batter?
    Battery Power
       Why should I turn off my modem when I'm not using it?
       How can I get more life out of my battery? 
    Hard Disks
       Why should I reformat my drive?
       Why does my 80 MB drive say it's 75 MB?
       What's the problem with reformatting 120 MB drives?
       How do I reformat my drive for maximum capacity? 
       What's the largest internal HD available? (520 MB)
       Where can I get it? 
       What are those vertical dark lines on my screen?
       What are those black spots on my monitor?
       How can I get rid of both?
    Serial Port
       How do I connect a printer to a Duo?
       What's the "internal/external" or "compatible/normal"
         switch in the Powerbook setup mean?
       How do I use non-com toolbox programs with an internal modem?
    Programmers Keys (needed for MacsBug)
       Where is the interupt/restart key on a Duo?
       Why don't they work when the Duo is docked?
       What alternative is available?

Part 2: Accessories

 * Expandability/Docks: What do I need a Dock for?

    Features: what can a dock do?
       Apple's Floppy Adapter
       Newer Tech SCSI Microdock
       Newer Tech Color Microdock
       Newer Tech Ethernet Microdock
       Lapis SCSI Dock
       Apple's Mini Dock
       E-Machines Powerlink Presenter
       E-Machines Desknet/Etherdock
       RasterOps DuoMate 8
       RasterOps DuoMate 16sc
       Apples Dock
       Apples Second Dock
    Coming Attractions
    FAQ's about docks
       Why can't I close the lid of my Duo while it's docked to a mini dock?
       How can I have the lid closed while docked to a mini dock?
 * Recommended
       Useful programs
         Battery Optimization
         Useful accessories
            AppleTalk Cable
            SCSI Adapter
            Hand Scanner
       Useful Sources of Information
         News groups
         FTP sites

Part 3: Repairs and Upgrades

 * Bugs/Problems: Help! My Duo just...

    Keyboard: keys unresponsive;
       rev A,B,C,D keyboards - how to tell which
    ADB: keyboard/mouse freezes up
    Enabler: What enabler you should use.
    Buzz: makes noise while asleep
    HD gone: duo in dock won't recognize Powerbook HD
    Missing Battery: duo can't find it's battery
    Battery Leads: pressing on palmrest crashes Duo
 * Sources: Where should I buy...?

    Ram Suppliers
    HD Suppliers
    CPU Suppliers
    Clearing Houses
 * Opening Duo's: How do I install...?

    Install ram       : easy for tech savvy people
    Install HD/modem  : mega hard - not recommended

 * Upgrades

    Apples 2xx -> 250
    Apples 2xx -> 270c
    Apples Duo LC040 Upgrade
    Apples Color Display Upgrade 
    MacProducts 2xx -> 33 MHz/40 MHz
    James MacPhails FPU add on

 * Modems

Introduction: What is a Duo?

What is a Duo?  A Duo is Apple's smallest lightest notebook
computer. Unlike other notebooks it has no floppy drive, no SCSI,
and no direct way of attaching an external HD or floppy drive. What
it does have is a serial port, phone jack (with internal modem),
and a 152-pin 32-bit PDS (processor direct slot) in the back
(called a PowerLatch connection), that accesses every signal line
on the 68030 processor.  This is true for all models as of today.

So what's that PDS (processor direct slot) for in the back of the
Duo?  It's what makes the Duo unique - the PDS is a wild card.  It 
allows adapters (called Docks) to connect directly and intimately
with the Duo's motherboard.  These adapters let you add features to the
Duo at the most fundamental level - something you can't do with
any other powerbook.  You can add ethernet, new video capabilities,
SCSI-2, accelerators, and other options that haven't even been
invented yet.

This expandability lets you tailor the same computer to entirely
different environments: at home, coupled with a floppy adapter and
external drive it's a stand alone home computer; on the train it's
the smallest, most portable powerbook; in the office, with a full
Duo dock, it's a business machine with 1 gig drive, ethernet, and
16" monitor - or whatever *you* choose to add.

What is a Duo?  It's whatever you want it to be.


The Models: What Duo's are/will be available?

The Duo 210 and 230 were released in October of 1992.  

The powerbook Duo 210 has a 25 MHz 68030 CPU with no FPU. It weighs
4.2 pounds (with battery) and measures 1.4 inches thick. It has an
internal microphone, speaker, standard size keyboard, and a
recessed internal 11 mm diameter trackball (smaller than
the powerbook standard of 19 mm diameter).  The 210 can accept a
maximum of 24 MB of ram.  The internal monitor is a 9" 4-bit
gray scale (16 grays) supertwist (passive matrix) with a resolution
of 640x400. There are four ports on the back: power in (*not*
compatible with other powerbook AC adapters), serial din-8 (for
appletalk, printers, external modems, etc.), RJ-11 modem (only if
internal modem is installed), and the powerlatch PDS slot on the
back.  There is no internal floppy drive.  The 210 was discontinued
in October of 1993.

The Duo 230 is identical to the 210, except it has a 33 MHz clockspeed.

The Duo 250 and 270c were released in October of 1993. Apple is
offering upgrades of previous Duo's to the 250 or 270c (current
cost has been quoted as $2000 for the 2xx to 270c upgrade).

The Duo 250 is identical to the 230, except it offers a 4 bit
gray scale (16 grays) *active* matrix monitor (sharper images) and
uses type II Nickel Metal Hydride (NiMH) battery.  The processor is
the same as that of the 230.  According to Apple the type II
batteries should run the 250 for 2.5 to 6 hours per charge.  IMO 
the improvements of the 250 are not worth the $1000 price difference
from the 230.

The Duo 270c offers three major improvements over the 250: color,
a maximum of 32 MB of ram, and a FPU.  The 8.4" active
matrix color display is slightly smaller than all previous 
duo displays, and offers two choices of resolutions: 16 bit
(thousands of colors) color at 640x400 (duo standard) or 8 bit
(256 colors) color at 640x480 (standard for all other Macs).The
improved display makes the 270c 1/10 inch thicker than the 230,
thus necessitating a different "hood" on the duo docks (see docks
below).  The type II NiMH battery is supposed to power the Duo for
2 to 4 hours.  Note: since the 290 and 290c are expected to
use a LC040 CPU, the 270c is the only Duo ever proposed that
has an FPU.  Oh and there's this little green light on the Duo
270c's cover.  It's to let you know if the Duo is asleep when it's
closed.  Light off - Duo shut down; light blinking - Duo asleep.

The Duo 280 will offer a 33 MHz LC040 CPU. The LC040 is a fourth 
generation Macintosh CPU without the integrated FPU (as in the 
Centris 610 and Quadra 605).  Apple intends to use the Duo's unique 
magnesium frame as a super heat sink for the processor. In addition to 
a tremendous increase in performance the 280 will accept up to 40 MB
of ram, and is expected to last from 2-4 hours per charge of its
NiMH type III batteries. The 280 will have a 9 inch 4-bit gray scale

The 280c is expected to be identical to the 280 but offer
a 16-bit color 8.4" active matrix display, as in the 270c.
Apple claims battery lives of 2-4 hours. (yea, right...)

The 290 and 290c: Apple says they'll ship in January of next year.  
We'll see.  The 290 and 290c will be identical to the 280 and 280c
with a 603 risc chip.  The 603 will be attached directly to the
motherboard, so the Duo's will be faster than they're Blackbird
breathren, however upgrades to the 290 motherboard for older Duo's
are expected to be more expensive ($500 for Blackbirds, expected
$1000 for Duos).  All this info is rough, take it with a grain of


Dockless Duo's: Do I have to buy a Dock?


I got one of the first Duo 230's off the line, and went six months
without so much as a floppy adapter.  I saw the Duo first and foremost
as the smallest, lightest, powerbook available (and besides, I couldn't
get a dock/adapter for love or money - they just didn't exist).

However, there are some things to keep in mind.  You have no floppy
drive, no SCSI connection, and no way to replace corrupt system
files - you're gambling.  If you're new to the Mac, or if the
Duo is your only Mac, I'd suggest you buy at least the floppy
adapter and external drive.  If you have access to a second Mac, the
SCSI adapters (Lapis or Newer Tech - see dock section) are the
cheapest option for installing a new system (via SCSI-HD mode),
and (IMHO) a wiser investment than the floppy adapter/external 

If you do go without a net (and even if you don't) here are a few
tricks that come in handy.  First, buy an Apple image writer cable
(a cable with a DIN-8 connection on both ends).  If you plug,
one end into the Duo's serial port and the other into a second
Mac you have an appletalk equivalent of a null-modem.  By turning 
on appletalk on both machines (via the chooser) you can transfer 
files in and out of your Duo.  This is slower than SCSI transfers,
but the only way you'll be able to install new software.  If your
system is shot though - you can't use appletalk.

A ram disk is great.  In addition to increasing your battery life,
running a system on a ram disk lets you have a redundant system
on your hard disk.  If the first gets corrupt you have the second as

If you do lose your system (I lost mine twice), start calling
stores in your area.  Most will let you plug your Duo into their
showroom Dock long enough to install a new system.  If they don't,
remember to forget them when you need to buy new peripherals.


Optimizing Duos: How can I squeeze the most out of my Duo?


Have you noticed that the title bars on your document windows
are the old black and white, 2-D type (as opposed to that neat
3-D effect in system 7).  The reason for this, is the system
4-bit gray scale Duo monitors do a strange thing with those
3-D bars.  They make them look like a current of liquid is
running under them - constantly in motion.  It's a neat effect
but Apple thought it would be distracting.  

So the system enabler for your Duo replaces the standard WDEFs
(window definition procedures) resource with the old black and white
versions.  If you want to get the 3-D effect you need to remove
this "patch."

To do this make a copy of your system enabler, and open
it with res-edit (if you don't know what res-edit is,
you probably don't want to be doing this) and remove the
WDEF resource.  Move your active system enabler out of the
system folder (save it - you might want to use it again) and
put your "edited" version in it's place.  Then restart
the computer.  I've never heard of any conflicts resulting
from this hack - but I doubt it's Apple approved.  You've 
been warned.

Also, a very usefull shareware program Strech 3.0, works
by overriding the systemd WDEF resource.  Since the enabler
is holding the last word for this resource, it overrides
Strechs overriding of the systems resource.  If you remove
the WDEF resource in the enabler (above) Stech works fine.


FPU stands for floating point unit.  It's a co-processor
(assitant brain) available in some computers dedicated to 
math tasks that require decimal point calculations.  The 
68030 macintoshes use a seperate chip, a 68882.  One of the
advantages of the 68040 chips though was to build this unit
right into the CPU.  The 68LC040 chips are cheaper, more 
battery friendly 68040 that have the FPU lobotimized off the

Most of what we do on a macintosh doesn't require (or is even
accelerated) by a FPU.  If you're just using Microsoft Word
to write a paper, or a telecom package to contact CompuServe
or the net, or playing your favorite game - it won't make a 
lick of difference.  Some users though run MathCad, or Mathematica,
or give Excel a real workout.  These programs benefit tremendously
from the use of a FPU (my SE/30 for example has half the clock
speed of my Duo 230 and runs some of my calculations 10 times
faster).  Hight level graphics programs, like RayDream Designer
also benefit from a FPU.

So why don't all Mac's have a FPU?  It uses battery energy (about
10% more).  As a result Apple chose not to put FPU's in the
210, 230, 250, and are using LC040 (FPU less 040's) in the
290 and 290c.  Currently the only Duo with a FPU is the soon
to be discontinued 270c.

The full Duo dock has a socket for a FPU, so you can add one,
and use the FPU with a 210, 230, 250, or 270c (the 270c is smart
enough to turn off it's own if a FPU exists in the Dock).  However,
the 290 and 290c will use LC040 CPU's, which are not expected
to be compatible with the 68882 FPU.

One last option exists.  A fellow named James MacPhail in Canada
has figured out how to wire a FPU into a Duo 210, 230, or 250.
See the "Upgrades" section for details.


What's ram, how's it different from a hard disk?  There are two
kinds of memory in your computer. Your hard disk is like a filing
cabinet, it takes effort to find what's in there and you don't
actually do any work there, but you can store a lot of stuff.  Your
ram is like the top of your desk. You have much less space, but
it's easy to find stuff there (hopefully) so you only keep the
things you're working on right there.  If you want to actually
work on a file, say a text document, you first get it from
your hard disk (your filing cabinet) then transfer it to ram
(your desk) and then start working on it.  When you're done
with the document, you save it back to the hard disk - just
like you put away your report in the file cabinet, to free up
desk space (ram).  One place this analogy breaks down though,
if at anytime your computer looses power (crashes or shuts down)
everything in ram (on your desk) disappears.  A significant 
incentive to save things to your filing cabinet often.

Duo's come with 4 MB of ram soldered onto the mother board.
You can then add one chip of any size (up to the machines
max - see the description of models for max ram) into the
single ram socket.  Note, if you are resonably comfortable
around hardware the ram installation is trivial and if you 
do it you *will not* void your warranty (see upgrades, installing
ram in section 3).  Most people add a 4 MB or 8 MB simm, this
(along with the 4 MB soldered) gives you a resonable about of
ram: 8 or 12 MB.  The standard 4 MB will not be enough for 
most users, 24 MB is nice (*real* nice) but often not worth
the expense (a 20 MB chip costs upward of $2000 last time I
looked).  A 8 MB chip costs (roughly and subject to daily
fluctuations) $300 (it's what I got when I first bought my
Duo - now I'll eyeballing larger chips though).

Ram Disks

What's a ram disk?  Using the same analogy we used talking about 
ram, a ram disk is like setting aside part of your desk as storage 
space.  Say when you're working on a special project and you know 
you'll need these ten files a lot.  You allocate part of your desk 
space as a temporary storage space, and set the files there.  The 
advantage is that you have quick, easy access to those files.  The 
disadvantage is that you have less space on your desk to actually 
do the work.

Why would I use a ram disk? In the computer, the ram disk will
appear just like a second hard disk on your Mac's desktop giving
you extra space to store documents and programs. Your computer will
be able to find these files much faster (so programs that are
located there or who use files stored there will run faster) and
easier (your computer will use less power for the same
tasks).  The disadvantage will be that you'll have less ram to
allocate to programs - you might not be able to run the same number
of programs at the same time, and if you loose power you 
***loose every thing stored in the ram disk***!  

What's special about ram disks for a Duo?  You can use a ram disk
on any computer, and have all of the above advantages.  However,
they're especially useful on Powerbooks and Duos.  Since you
have a battery (as opposed to being dependent on a wall
outlet) power failures (a popped circuit breaker, or Joe down
the hall tripping over your power cord) won't cut off power to
your CPU - that means RAM disks are less likely to evaporate on
a Duo.  Since a ram disk takes up less power than a hard disk,
your battery will last longer.  Here's the real beauty though.
By having a ram disk with a copy of your system folder on it,
you have a backup - in case anything goes wrong with your 
system.  You can also use this trick to reformat your HD,
or install a new system - even without a dock.  Caution, a ram
disk should be thought of as a backup, or temporary HD - you
should keep a second system on your HD in case anything happens
to the ram disk.

How do I create a ram disk?  There are a lot of programs for
creating ram disks.  The easiest is the memory control panel
in your system.  Just open it, turn on the ram disk, and 
allocate as much ram as you want to it (you should keep at 
least 4 MB for running the computer though).  Then restart.
The RAM disk icon will appear on your desktop, and you can
just drag a copy of your system or program onto it as if it
were a second HD or floppy.  To make the RAM disk your system
disk, you need to open the startup device control panel, click
on the ram disk, and restart.  There's also a useful program
called AppDisk, that will be talked about in the recommended
software section.

How do I get rid of a RAM disk?  Just drag it into the
trash.  Depending on how you made the disk you might need
to delete it's contents first, and might need to restart
the computer to get the ram that you allocated for it back.


When Apple introduced the Duo, they included a new kind of battery.
The Duo uses a Nickel Metal Hydride battery (NiMH) that has a 
longer life than the Nickel Cadmium batteries (NiCAD) of the
earlier power books.  With the release of the Duo 250 and 270c,
Apple is including a second kind of Nickel Metal Hydride battery,
called "type II" (NiMH II) - the type II battery can be used
in the 210 and 230, but you must first install new power management
software.  You can use extra type I batteries in the 250
and 270c - they just won't last as long.

On the side of the type I battery is a 2-position switch.  It
doesn't do anything.  It's just an easy way to mark your battery as
"full" or "empty" - so you can store a couple of 'em in the same
bag and easily find a full one when you need it.  The number on the
side is a serial number - it's unique to your battery.

Type I batteries will work in the Duo 250 and 270c as well as the
210 and 230 with upgraded (type II compatible) power management 
software - they just won't last as long as the type II batteries.
The Type II battery can be identified by two methods. The Type II battery
release button is smaller than the original Type I. Also the Type II
battery label is marked with Type II logo and has product marketing number

The high capacity Type II NiMH battery will work with all Powerbook Duo
computers. However, the system software has to be updated to use this new
battery in older Powerbook Duos. If a Type II battery is placed into an
older Powerbook Duo 210/230 without the software upgrade, the system will
not run from the battery (even if fully charged). The system will work from
an AC power source; however, the battery will not be charged.

Some of the battery rechargers (that clip to the side of the AC adapters)
shipped prior to July 1993 will not be able to download new code required
to charge the new Type II battery. Although these systems will work fine
with existing Type I batteries, if a Type II battery is placed in a slot,
the LED will glow red (indicating the battery is not recognized). In this
case, the battery will not be charged.

The battery serial number you see with DuoMon or similar
software is also unique to your battery.  The first four
digits though tell you if it's a type I or type II Nickel Metal
Hydride battery.  The prefix "0010" is for type I batteries,
the prefix for type II batteries is unknown.

NiCAD batteries have a problem.  If you don't discharge them
completely they start remembering when you regularly plug in the
charger, and start quitting at that point.  To prevent this you need
to regularly completely discharge them (often called "conditioning"
the battery).  The Duo's use only NiMH batteries, which don't have
this problem, so you never need to condition (completely discharge)
a Duo battery.  Note: Apple is including "conditioning" software
with the type II batteries.  Apple has said it "can't hurt", but
the prevailing sentiment is that it's a placebo.

To insert a battery, Apple recommends you first slide the latch open
until it "click's" and becomes rigid (note: it is possible to slide
the latch too far.  If you do so just slide it back). Then, holding
your Duo vertically insert the battery all but 1 cm into the slot,
and let it drop the remaining 1 cm into the opening.  Make sure
that the grooves on either side of battery compartment are aligned
with the groves on the latch, then slide the latch closed while
holding down the button.  Then release the button. If you don't
slide the latch all the way open before inserting it in the Duo
your battery might not make proper contact with the battery leads,
and cause problems.  The usual symptom is an inability to charge
your battery.

Apple will release a type III battery with the Duo 280 and 280c.
As a rule of thumb the type II batteries are 50% better than type
I's and type III's are 15% better than type II's.  Your mileage
may vary.

Battery Power:

The Duo is a Portable computer - you can use it in planes, trains,
and automobiles - so long as your battery holds out.  Then you have
a $2000 paperweight.  The basics of increasing your battery life
boil down to:

* Turn off your telecommunications programs when not in use.  
This is a big one.  

* Turn off your modem when you don't need it.  This is not the
same as quitting telecom programs.  You computer keeps the
modem on constantly so you can receive faxes automatically,
but this can be a drain on your battery.  You can turn it off
with the "express modem" control panel, or you can install
the shareware fkey "kill'em" if you're familiar with using
resedit to install fkeys.

* Use a ram disk for your system and applications.  In addition to
saving battery life, you'll also appreciate an increase in speed.

* Spin down your hard disk as much as possible.  You can do this
with either CPU, NEP or any other power management utility 

* Turn off appletalk when not in use.

* Set your processor to 16 MHz

* Allow processor cycling

(this section under construction, details will be included in later
  versions of the FAQ)

Hard Disks:

Have you looked at your 80 MB drive recently?  Odds are it's
formatted to about 75 MB.  Stranger still, if you look at it with
a hard disk utility (APS Powertools for example) you'll notice that
there is still unformatted space on it.

Apple buys drives from many different sources, and they come in all
types - and sizes.  To standardize them Apple formats all it's
drives to the smallest maximum size of the various disks.  That
means your 80 MB drive could be a 75 MB drive - or larger.  This
is true for all drives - not just the 80 MB ones.

So it's possible - even likely - you can get an extra couple of MBs
out of your drive.  To do this you have to reformat your drive -
totally erase and rebuild it.  Only you can decide if the process
of *backing up* the entire contents of your drive, reformatting the
drive, and then returning all the data to the drive - is worth 3
extra MB of disk space (that's what I got out of my first 80 MB
drive).  Depending on the size of your drive and how you're backing
up this process could take minutes or hours.

IMPORTANT: reformatting the drives to certain disk capacities can
can cause the computer to not recognize the drive.  These capacities
are supposed to be multiples of 128.  So if you format a disk to
128, 256, etc. it will not be recognized by the mac.  You can get
around this by formatting the drive to 127 or 129 MB with no
problem.  Apples HD set up tool 7.2 has an undocumented patch
for this bug, and the ROM of newer machines (only 660av and 840av
so far - expect it in the 250 and 270c) also correct this problem.

(more details will be included in future releases, please mail
  recommendations for reformatting software and any details to
   me for inclusion)    

The largest internal hard disk for the Macintosh Duo is a Toshiba
520 MB drive.  It's just been announced, but hasn't hit the market
yet.  A 324 MB and 213 MB version of the Toshiba drive are available
from APS Technologies.  Expect about $800 and $500, respectively.
The Toshiba drives are *not* easy to install in the Duo's (as opposed
to the 40, 80, 120, & 160 quantum GO drives - also available at
APS and other sources) - but it is possible.  Tech installation
recommended.  Quantum just announced it will be shipping a 340
and 500 MB drive soon.  Don't have anymore details.

[APS Technologies, 800-354-1213, FAX 816-483-3077, Intn'l 816-483-6100, 
  6131 Deramus, PO Box 4987, Kansas City, MO, 64120-0087]


Have you noticed dark vertical lines on your display?  They're a
result of the passive matrix display on the 210 and 230, and extend
from vertical lines from your windows or desktop pattern.

Your display is very sensitive to ambient light.  You can get rid of
these lines but adjusting the contrast on your display, but if you
move to another location - with different light - they'll be back. 
If the lines bother you, make a habit of adjusting the contrast
whenever you set up your Duo.  You might also want to consider the
new Duo 250 or 270c, whose active matrix displays won't have this

Do you have black spots on your monitor?  They are not dead
pixels - this phenomena doesn't exist in passive matrix displays
(as in the 210 and 230) although it might creep up in the new
(250 and 270c) monitors.  If you have dark spots on your 
passive matrix monitor it might be dirt trapped under the 
display.  Best way to get rid of it (and it doesn't always work)
is to set the monitor in the vertical position, and gently tap
it near the dark spots with a coin.  Be *very* careful not to
crack or scrape the monitor.  This can cause the dirt to shake
loose and fall to the bottom of the display (out of site)
and removing the dark spots.  I have not tried this - proceed
with caution.

Serial Port

The undocked Duo has a single serial port, which is implemented in the
so-called "combo" SCSI/SCC chip. When the Duo is docked to a device
with its own SCSI or serial ports, then the internal combo chip is
disabled, and superceded by hardware in the dock itself. The low-level
device drivers hide this from you, so a program which opens a serial
port doesn't need to know any specifics about the particular hardware.

The single serial port corresponds to port A, or the "modem" port as
it would be called on the more standard two-port Macintosh. Don't
confuse this with the internal modem, which is completely separate.
Thus, if you attach a serial printer to the serial port, you need to
tell the printer driver to use the modem port, and not the printer
port (since there isn't one). If you have Appletalk turned on (in the
Chooser), then it grabs the port for its own use. To use a serial
printer, Appletalk must be turned off (Appletalk printers, of course,
need Appletalk to be turned on).

An internal modem installed in a Duo interfaces directly to the
microprocessor bus, and does not use a serial port. The PowerBook
control panel will have a Modem entry, allowing you to select either
"compatible mode" or "normal mode" (in older versions of the system
software, these modes are called "internal modem" and "external
modem," respectively). Confusingly enough, you almost never want to
select "compatible" (or "internal modem"). What this does is replace
the low-level serial port A device driver software with one that talks
to the modem instead of the serial port itself. In this case, a
printer driver, for example, would find itself sending characters to
the modem instead of spitting them out the serial port, and you won't
be able to print. The only time you want to use this option is if you
are using an old telecommunications program which does not know how to
talk to the internal modem directly via the Communications Toolbox. By
selecting "compatible" mode, the program can open the "modem" serial
port and it will actually wind up talking to the internal modem.

Programmers Keys

You ever notice those two keys that appear on all macs?  Usually on the side
or the back?  One of those keys is the "interupt" and the other is the

If your mac freezes *don't* just turn it off.  This lets the head on your hard
drive just drop on the media.  Nine times out of ten, this won't do any damage
- but the potential exists for some real damage.  The restart key though does
not cause this problem.  On a Duo you send a restart signal by holding the 
control, command, and hit the power key (that triangle key right under the 

The interupt key is a way of stepping out of the mac OS shell into a command
line interface.  Most of us will never use this, but programmers use this key
to access a low level debugger called macsbug.  The key combination to send
this signal on a Duo is hold the control key and hit the power key. 

Neither of these key combinations work while the Duo is docked in a full dock.
A software init called programmer's key 1.4.2 will let you use the command and
"`" key to drop into the line interface.

Expandability/Docks: What do I need a Dock for?

The Duo is a great powerbook - light, fast, small, and powerful.
Additionally it is the only expandable powerbook.  With the right
peripheral you can add external monitors, floppy drives, SCSI-2,
accelerators, ethernet, or features that haven't even been thought
of yet.  

Below is a list of the Docks currently available, and the features
they offer.  MacWorld recently published a table of these docks and
their features (page 34 of MacWorld, Oct. 1993).  If you haven't
read it, don't look it up.  If you have - be warned there are
numerous mistakes.


- Floppy: a port for connecting an external floppy drive.

- SCSI(): a port for connecting SCSI devices (HD's, CD drives, etc.).
    In parenthesis I've indicated whether the SCSI is Apple's new
    30-pin powerbook SCSI (30) or the standard DB-25 SCSI connector (25).

- SCSI-HD: lets you use your SCSI port (above) to connect your
    Duo to another Mac as if it were a hard disk on that computer.
    Very useful for fast file transfers and installing new
    operating systems or other software.

- Serial: a port for connecting external modems, printers, or 
    using an appletalk connection to other Macs (works only if
    your operating system is running)
- ADB: apple desktop bus for connecting external keyboards, mice, 
    10 key pads, and other input devices.
- RJ-11: a phone jack for the (optional) Duo internal modem.

- Video(): a DB-15 port for connecting external monitors, some 
     devices offer greater numbers of colors, or access to larger
     monitors.  The number in parenthesis is the depth of the
     video in bits.  1-bit is 2 colors, 2-bit is 4 colors,
     4-bit is 16 colors, 8-bit is 256 colors, 16-bit is
     thousands of colors, 24-bit is millions of colors.
- PAL: composite video out, lets you connect a European TV as
     an external monitor.
- NTSC: composite video out, lets you connect an American TV as
     an external monitor.
- Sound: a sound out connector, lets you add external speakers.

- Ethernet: an ethernet card, allowing you to connect at very 
    fast transfer rates on ethernet networks.
- nu-bus: a nu-bus socket for adding cards for SCSI-2 connections,
    second external monitor, faster video, multimedia, etc.

- Open(): my own notation.  This means the device does not cover
    the Duo's internal ports (in parenthesis), allowing
    you to use these as well as whatever the dock offers.

The following is a description of those peripherals I'm
aware of (10 as of today).  Following each is a quick summary
of the features offered.


1) Apple's Floppy Adapter: For about three months after the release
of the Duo's this was the only dock.  It leaves the modem and serial
ports of the duo uncovered, and has a floppy and ADB port.  Manufactured
by E-machines, sold by Apple computers, expect about $80.
={Floppy, ADB, Open(Serial, RJ-11)}

[Apple Catalogue (warning: high-prices, if you're in school
  contact your EDU source first) 1-800-795-1000]

2) Newer Technologies SCSI Microdock: A great idea.  Same form factor as 
the Floppy adapter, thus leaving serial and modem ports open.  It has a 
SCSI and ADB port - only.  Supports SCSI slaving of the Duo to a second Mac 
for data transfer with the same cable you use to hook up an external SCSI 
device.  Vice a versa, you can use the SCSI slave cable to hook up external 
devices also (the one difference between it and the Lapis version).  This 
device was developed by Computer Care and is licensed exclusively to Newer 
Tech.  Runs about $135 at Mac's Place - they seem to have the best price on
={SCSI(30), SCSI-HD, ADB, Open(Serial, RJ-11)}

[Mac's Place 1-800-814-0009  FAX  1-800-881-3090
  8461 154th Ave NE, Redmond, WA 98052-9917]

[Newer Technologies, 1-800-678-3726; 316-685-4904; FAX 316-685-9368
  7803 E. Osie, Suite 105, Wichita Kansas 67207]
[Computer Care, 612-371-0061, FAX 612-371-9342]

3) Newer Technologies Color Microdock: Same form factor as the
Apple floppy adapter it's under 8 ounces and offers 8-bit color
on monitors under 16" in size (4-bit color above that).  In addition
to the monitor port, the color microdock adds a sound out and
ADB port.  Note this might be the same product "BookView Duo"
from Computer Care, but I have not been able to confirm this.
Retails at $345.
={Video(8-bit), ADB, Open(Serial, RJ-11)}

[Newer Technologies, 1-800-678-3726; 316-685-4904; FAX 316-685-9368
  7803 E. Osie, Suite 105, Wichita Kansas 67207]

3.5) Newer Technologies Ethernet Microdock: I see a pattern here.
Newer tech has packaged ethernet into the microdock formfactor.
It's a handy idea for system admins on the run, and runs about 
={Ethernet, ADB, Open(Serial, RJ-11)}

4) Lapis SCSI Dock: Same idea as the Newer tech SCSI microdock, and it beat 
'em to market.  Form factor identical to the Apple floppy adapter.  You can 
use SCSI disk mode with a standard 30x25 or 30x50 cable by holding the 
control key on startup, rather than using the hard to come by SCSI HD mode 
29x50 or 29x25 cables.  However you can't use the 29x50 cable to use and 
external SCSI device - like you can with the Newer tech version (the only 
difference I've heard between the two).  Everyone who's talked to me about 
it is in love with it.  Expect about $160, available at Mac's Place.
={SCSI(30), SCSI-HD, ADB, Open(Serial, RJ-11)}


5) Apple's Mini Dock:  The standard by which all others are judged.
It connects to the back of the duo, and most closely resembles a
three hole punch.  Covering the Duo's internal modem and serial 
ports, if offers two serial ports, a RJ-11 port, an ADB port, floppy
port, sound in and out (not stereo), and video out (8-bit up to 16" 
monitors).  This device is manufactured for Apple by E-Machines.
Note: when you lock one of Kensington's microsavers to the minidock
you can still remove the Duo!  That means a thief will have to be
satisfied with your dou, but the dock is safe.  No idea if they're
going to fix this bug.
={Floppy, Video(8-bit), SCSI(30), SCSI-HD, RJ-11, Serial, ADB, Sound}

[Apple Catalogue (warning: high-prices, if you're in school
  try to buy from your EDU source first) 1-800-795-1000]

6) E-Machine's Powerlink Presenter:  One of the first duo docks, the
Presenter is designed for (surprise!) presentations.  It does not
cover the duo's phone jack or serial port, and offers a floppy
port, ADB port, sound out, video out (8-bit up to 16" monitors),
and PAL and NTSC video out.  

NOTE: The Presenter is substantially larger than the microdocks
but has no support.  It hangs on the Powerlatch.  Some people
have reported periodic system freezes, and suggest this is due
to the strain on the connection.  This is speculation.

={Floppy, Video(8-bit), PAL, NTSC, ADB, Sound, Open(Serial, RJ-11)}

[E-machines, 503-646-6699, FAX 503-641-0946, FaxBack 800-541-4787
  9305 SW Gemini Dr., OR 97005, USA]

7) E-Machine's Desknet AKA Etherdock: Same form factor as the
Apple's mini dock, the Etherdock (also billed as Desknet) has the
same connections - almost.  According to E-Machines specs you loose
the RJ-11 pass through for the internal modem, and gain ethernet.
This means you have to disconnect your Duo to use the internal
modem (you can use an external modem, via the serial port though). 
It comes with a 10BaseT ethernet connection, and support 8-bit
video on screens up to 17".
={Floppy, Video(8-bit), SCSI(30), SCSI-HD, Ethernet, 2 Serial, ADB, 

[E-machines, 503-646-6699, FAX 503-641-0946, FaxBack 800-541-4787
  9305 SW Gemini Dr., OR 97005, USA]

8) RasterOps DuoMate 8:  It does not cover the Duo's internal
serial and RJ-11 ports, and adds 8-bit video, NTSC, PAL,
ADB, Floppy and sound out ports.  It's shaped a lot like the
E-Machines presenter, but a "foot" has been added to support
the dock.  This foot makes the dock a little safer for your
connection, but also makes it the thickest Mini Dock.
It has a 32 bit video data path that is supposed to result
in faster screen refreshes than any other dock (I haven't
tested this claim yet).  Expect about $350.
={Floppy, Video(8-bit), PAL, NTSC, ADB, Sound, Open(Serial, RJ-11)}

[RasterOps, 408-562-4200, FAX 408-562-4065, FaxBack 800-SAY-COLOR
  2500 Walsh Ave, Santa Clara, CA 95051 USA]

9) RasterOps DuoMate 16sc:  This is the one I bought.  It adds
16-bit video on monitors under 16" (8-bit after that) and a
standard DB-25 SCSI connection to the DuoMate 8.  Short of the full
dock, this is the only dock to offer better than 8-bit video, and
across the board it's the only one that has a normal SCSI connector
(which means you don't have to buy a whole new set of cables for
your powerbook alone).  It supports SCSI-HD mode with a standard
25x25 or 25x50 cable.  Note: PAL and NTSC require a special
(not included) adapter.  This adapter costs big money (I think
in the $200-300 range).  Expect about $545.  
={Floppy, Video(16-bit), PAL, NTSC, SCSI(25), SCSI-HD, ADB, Sound,
  Open(Serial, RJ-11)}

[RasterOps, 408-562-4200, FAX 408-562-4065, FaxBack 800-SAY-COLOR
  2500 Walsh Ave, Santa Clara, CA 95051 USA]


10) Apple's Dock:  The works.  Simply put, if you want everything
(except dock portability), you want the full Dock.  It offers all
the above connections, plus a bay for a hard disk, and slots
for two full nu-bus cards.  The video ram is expandable up
to 1 MB (16 bit on 16" monitors) and you can add a FPU to the dock.
This is the only way to add a FPU to non-270c Duo's, and you
only have use of it while the Duo is docked.  The full dock 
is about the size of a IIci, and you insert the duo into a 
bay in the dock, totally enclosing the Duo (unlike the mini
docks) so you cannot use the Duo's internal display and keyboard
with this dock. There is a floppy drive built into the dock
(different from a port for an external floppy drive). 
With the thicker 270c, Apple has started selling the full Dock
with a larger hood.  You can add this hood to existing
docks for about $70.  The new hood has a dust cover over the 
powerbook slot so it's easy to spot which docks can use the
270c.  The full dock is sold in two configurations: one stripped,
and one with a 230 MB HD, 1 MB VRAM (instead of the standard
512K), and FPU.  All of these features can be added if you buy
the stripped configuration.  Apple price is about $500.
={Floppy *Drive*, Video(expandable), SCSI(30), ADB, Sound,
  nu-bus, Serial, RJ-11}
Full Dock II: (released May 16, 1994)

Apples second generation dock has built in ethernet, fpu, 
1 MB of video ram standard, and a 32 Kbyte cache.  The cache
and fpu will only acclerate 030 duos that are docked - 040
and 603 Duo's will just ignore them.  Other than that it's
expected to have the same form factor and features of the
Full Dock I.  A hood upgrade will not be necessary to insert
color Duo's.
={Floppy *Drive*, Video(16-bit), SCSI(30), ADB, Sound,
  nu-bus, Serial, RJ-11, ethernet}

Coming attractions:

Apple will be releasing a second generation full dock with
built in ethernet.  This Dock will also have standard 1 MB
VRAM (8-bit video up to 21"), FPU standard, and a 32 KB
cache.  Apple intends to continue to ship the current version
for users who don't want to pay for these enhancements.

RasterOps is working on a third mini dock.  All they'll
say is it will have "enhanced video capabilities" - my guess
is 24 bit video.  DuoMate 24sc?

Newer Technologies is working on a ethernet mini dock.  It'll
come in the "floppy adaptor" form factor and have 10B-T and 
and ADB ports.

FAQ about Docks:

Why can't I close the lid of my Duo while it's docked to a mini dock?

  When you close the Duo's lid, it sends a signal to the Duo telling
  it to go to sleep.  Mini docks don't support sleep while docked.
  As long as the lid is down, it'll keep sending these signals
  and you'll keep getting error messages.

How can I have the lid closed while docked to a mini dock?

  A neat feature that seems to be added with Duo enabler 1.0.
  If you shut down your duo, then dock it, then powerup from
  an external keyboard *with the lid closed* you won't get those
  error messages.  This works with the Apple mini dock and with
  my RasterOps 16sc.


Recommended Software:

* CPU: Connectix PowerBook Utilities.  The first commercially available
utilities for the powerbook (and Duo) offer file synchronization,
battery management, and other useful utilities.  Note: the 
security utility modifies your system *without* letting
you know.  If you have a customized system, caution is advised.
The de-installer deletes the added code to your system file.
This bug/feature alone has turned me off on CPU, your mileage
may vary.

* NEP: Norton Essentials for the PowerBook.  Similar to CPU, and
what I use.  The difference between CPU and NEP is very slight,
and it's just a preference call as to which implementation is 
better suited to your tastes.  However you do want one or the
other. *Note: Symantec has just announced that they will discontinue
NEP.  I'm not throughing mine out, but if you're going to buy one,
I'd pass on it.

* DuoMon:  A great freeware application by Mike Blackwell
(mkb@cs.cmu.edu) available by ftp at sumex-aim.stanford.edu and
other sources.  This utility tells you everything you wanted to
know about your Duo's battery and settings.  Indicators show
brightness and contrast settings of the display, clockspeed,
battery id #, battery temperature, current battery usage (useful
for answering question like "How much am I saving by spinning down
my HD, or by using BBedit instead of MS Word?").  You can even
start a graph of power usage that will plot how the battery usage
goes up and down over time.  Also, a smaller window can be left
on that shows you current battery level in watts and volts, so
you have an idea how much power is left in your current battery.

* PowerClick: A neat shareware extension by Daniel Segel
(daniels@netcom.com) available by ftp at sumex-aim.stanford.edu 
as /info-mac/gui/power-click-101.hqx on mac.archive.umich.edu
as /mac/system.extensions/cdev/powerclick1.0.1.cpt.hqx.  
Did you know that the mouse buttons on your Duo are
wired separately?  Not true for other powerbooks, this feature
offers the potential of having the two buttons do different
functions.  Daniel's code lets you set either button to do a single
click, click lock, double click, or nothing.  Setting the bottom
button to nothing is a very useful option for those of us who use
our Duo's in our lap, say lying back in the sofa.  I don't know how
many times the weight of my Duo has accidentally clicked the lower
button.  (Note: not to be confused with "Powerclicks 2.0" - with an
"s" - which is an entirely different program)

* Disinfectant: the internets answer to the latest virus.  Duo users tend 
to rely on telecom and slaving other CPU's floppies, so they're more likely 
to get a virus than the average user.  Also, those without docks can be 
crippled by a bug chewing on their system - so they're more vulnerable as
That said, you should have Disinfectant on all you machines.  John Norstrad 
keeps the latest release (available via ftp) at ftp.acns.nwu.edu in 
/pub/disinfectant.  Disinfectant is freeware.

           *** latest release is Disinfectant 3.5 ***

*Duo Extension Picker:  I haven't tried this one myself, but have gotten
a lot of mail asking about it.  It's a two part program (extension and
control panel) written by Alan Steremberg (alans@engin.umich.edu) that 
detects whether or not (and to what) your Duo is docked at startup.  Then
loads a set of extensions you choose.  This way you can have your Duo
load the CD init and MacTCP when you're docked to the full dock, but
not load 'em when you're using your mini dock, or going dock-less.  Kool
idea, and available at sumex-aim.stanford.edu.

(this part still under construction, please send any recommendations you 
  think would be valuable)

Recommended Hardware:

* APS SCSI Boy:  If you have a Dock (Micro, Mini, or Full) that uses an
Apple HDI-30 pin SCSI port - you want this.  It's a small metal adapter
that inserts into your HDI-30 SCSI port and converts it to a standard
DB-25 SCSI port.  That means for $29, you can use all your existing 
cables on your powerbook.  It's also a lifesaver if you're on site,
forgot a powerbook specific cable, and need to scrounge.

[APS Technologies, 800-354-1213, FAX 816-483-3077, Intn'l 816-483-6100, 
  6131 Deramus, PO Box 4987, Kansas City, MO, 64120-0087]
* Targus PowerPac: padded Duo case.  It's hard to find a case you like, 
even worse if you own the Duo.  This is the one I settled on.  It measures 
14" x 11" x 2.5" with an outer pocket that measures 13" x 9" x 2".  The Duo 
fit's in the main compartment *sideways* - an included divider leaves 
exactly enough room for a floppy adapter and floppy drive (although I 
usually use the space for the power adapter and a paperback novel).  The 
nylon case comes in five colors (blue, teal, gray, purple, and black), and 
there is a leather version too.  It runs $39 at MacWarehouse, $99 if
you're into leather.

[MacWarehouse, 800-255-6227, FAX 908-905-9279
  1720 Oak St., PO Box 3013, Lakewood NJ, 08701-9917]

* MagentaCase/MagentaCase Lite for the Duo: case *designed* for the Duo.  
Magenta systems make a nice powerbook case, better still they just released 
a version designed specifically for the Duo.  The cases are described as 
MagentaCase *for the Duo* - not to be confused with there MagentaCase.  The 
case (black) has a central pocket, document, and accessory pocket.  The 
lite version (black or burgundy) has only one pocket.  They run $55 and 
$22, direct.  Disclaimer - I've never seen/used one.

[Magenta Seven, Inc. 800-284-3957, CompuServe 75160,3030
  5109 Holly Ridge Drive, Suite 209, Raleigh NC, 27612-3146]

* Imagewriter (Appletalk) Cable:  An essential.  This $11 cable is
available at any computer supply store or mail order house.  It has
a DIN-8 connection on both sides. Plugging one end into your Duo's
serial port and another into the serial (printer or modem) port of
another Mac lets you Appletalk between them -to transfer files or
use the other computers floppy drive.  If you have a "Dockless" Duo
you can't survive without it.

* Kensington Microsaver security cable: Useful.  This cable attaches to all 
Duo docks (including the micro docks).  By locking the cable to the 
"security slot" in the dock and to a table leg you can discourage your Duo 
from walking off (most docks will not let you remove the Duo when the cable 
is attached).  Will not prevent a dedicated thief (nothing will) but will 
discourage crimes of opportunity.  Sold by MacConnection (among others) for 
about $40.

[MacConnection 800-800-2222  FAX 1-603-446-7791
  14 Mill Street, Marlow, NH 03456]

[Kensington 415-572-2700]

* Replacement trackballs:  OK, this ones a luxury.  But if you want
to add a little personality to your Duo, you can replace the
Apple trackball with a couple options.  The first is a 11 mm
marble, they're kind of hard to find but people have reported they
work great.  The second option is a day glow ball made just for
the Duo's.  They're available in four colors (the green, yellow,
orange, and violet of the apple logo) for $10 ea. or $20 for all four
from APS tech.  They're cute, I haven't tried 'em yet.

[APS Technologies, 800-354-1213, FAX 816-483-3077, Intn'l 816-483-6100, 
  6131 Deramus, PO Box 4987, Kansas City, MO, 64120-0087]
* LightningScan Portable: portable hand scanner.  This hand scanner is 
battery operated, 400 dpi, 8-bit gray scale, and has OCR.  The device 
connect via a serial port, where as most connect via SCSI.  That means this 
is one of the few scanners you can use with a Duo without a Dock.  You get 
30 minutes of scanning per charge, but realize that that's 30 minutes of 
actual scanning.  You don't use juice while the device is just turned on.  
I've got a lot of e-mail raving about this, and am thinking about getting 
one myself - but I have no first hand knowledge of it.  With all the 
necessary software for scanning and OCR, it runs $399 through MacWarehouse.

[MacWarehouse, 800-255-6227, FAX 908-905-9279
  1720 Oak St., PO Box 3013, Lakewood NJ, 08701-9917]

* Powerbook Floptical.  Iomega is releasing a $399 battery operated 21 MB 
floptical drive.  It's going to be sold exclusively through the Apple 
catalog.  It's a SCSI device and also reads floppy disks.  Teamed with a 
Duo SCSI adapter it makes a killer option for Duo users (PB 100 users 
should also take note).
* Duo Battery Charger.  Excerpt from add, (I have no personal experience):
"Lind Electronic Design is now shipping the SuperCharger II for the PowerBook
Duo NiMH batteries.  The SuperCharger II is specifically designed to charge
the Duo batteries as quickly as possible with no time consuming trickle
required.  This unit will also condition the battery to prevent and correct
the loss of capacity due to 'memory effect'.  Lind model SBC-2 available
now for $149.95 (visa m/c accepted)" - note NiMH batteries are not supposed
to have any "memory effect", I have no idea why they are selling a conditioner

[Lind Electronic Design, Inc.  612-927-6303  FAX 612-927-7740
  6414 Cambridge St., Minneapolis, MN  55426]

* PowerPlate 4x: Duo Battery Plate (4x the power of type I NiMH):  Technoggin
announced a 3.6 lb lead acid battery that fits under the bottom of the Duo
and has a life time of 4x NiMH I or 3x NiMH II Duo batteries.  It's supposed
to cost $299.95 and will begin shipping this quarter.  Note: VST also expects
to ship a version of this battery called the ThinkPak Duo - no details.

[Technoggin Inc  513-321-1777 or 800-305-7936  FAX 513-321-2348
  1018 Delta Ave, Cincinnati, OH  45208]

[VST Power Systems Inc.   508-287-4600   FAX  508-287-4068
  1620 Sudbury Road, Suite 3, Concord, Mass.  01742

(this part still under construction, please send any recommendations you 
  think would be valuable)

Recommended Sources of Information:

* MacUser: one of the staples.  A monthly publication that reviews
hardware and software for the mac.  A must read.  Expect to find
detailed reviews and comparisons of existing hardware and software.

[MacUser Subscriptions, US $27/year, Non-US $43/year, 
 MacUser, PO Box 52461, Boulder, CO 80321-2461]
* MacWorld: the other staple.  Information is a little more current,
a little more prone to make errors but essentially MacWorld
and MacUser are vol. I and II of a months required reading. A must 

[MacWorld Subscriptions, US $30/year, Canada/Mexico $48/year,
 Other countries $99/year, 800-234-1038, 800-288-6848, 415-267-1743
 Subscriber Services, PO Box 54529, Boulder CO, 80322-4529]
* MacWEEK: the most current source of information about the Mac.
While MacWorld and MacUser have detailed information about what's
been released, MacWEEK talks about what's going to be released.
Since information is so fresh, it's more likely to be inaccurate,
but you'll read about it in MacWEEK before anyone else hears about
it.  You'll also pay more for it, annual subscription is $99.

[MacWEEK Subscriptions, US $99/year, International $200/year (609)786-8230
 Customer Service Dept., MacWEEK, c/o JCI, PO Box 1766, Riverton NJ 08077]

* News groups.  Well, if you're reading this odds are you know about
them.  Recommended are:

    comp.sys.mac.portables  -  the home of the powerbook and mobile
    comp.sys.mac.hardware   -  if you have questions about new hardware
                                or non-portable CPU's this where to go.
                                Dale Adams - Apples 040 pro - visits
    comp.dcom.com.modems    -  if you have a question about your 
                                modem or telecom in general, this is
                                where the gurus and phone phreaks live.
    comp.sys.mac.announce   -  the really important stuff - the latest
                                virus, major software upgrades, Apple
                                press releases - come here.  Not a lot
                                of traffic, but pay attention to what
* FTP sites.  

    mac.archive.umich.edu   -  /mac/util/powerbooks
                                The latest Duo FAQ, as well as other
                                useful info and programs.  Note, if
                                you're on AFS you can cd here - no
                                waiting in the FTP queue like at sumex!
    sumex-aim.stanford.edu  -  The internets mac clearing house.  If
                                it's remotely useful or informative
                                - it's here.
    ftp.acns.nwu.edu        -  /pub/disinfectant
                                If anything, powerbook users are more
                                vulnerable to viruses.  This is the home
                                of Disinfectant - the standard internet
                                answer to known viruses.  Make sure you
                                have the latest copy.

Bugs/Problems: Help! My Duo just...

The following are known bugs with the Apple Duo's and some
easy solutions.  Standard disclaimer: if you're not hardware
savvy, have a tech do all the hardware work - a $2,000 computer
is generally worth a $30 repair by a pro.  If you find bugs 
not described here, or these solutions don't help, call 
Apples support line (800-SOS-APPL).  


Problem:  Your space bar or return key or delete key are 
unresponsive (you have to hit 'em two or three times to
work, or they don't work at all).

Solution:  There's more than one.  You could have the old
rev A keyboard.  It could also be due to the 3 screws under the
keyboard being too tight, or just dirty contacts.  You can 
remove the keyboard (see "opening the duo: ram") and look at the
serial number on the bottom.  If it ends in "a" you have the
bad keyboard - get it replaced while your warranty still exists
- no charge.  If it ends in "b" you have a rev B keyboard.  Most
people had no problems with the rev "b" - but some did.  The
latest keyboard (officically released for the 250/270c only) is
the rev "c" - serial number ends in a c.  Apple is now using only the
rev c for a replacement part - but they won't take out a rev b under
warranty unless you're having problems with it.  I haven't heard any
complaints about the rev "c".  If you still have problems loosen 
the three screws under the keyboard.  If you still have problems have 
a tech clean the connections.

  Evidently Apple has released a rev D now, I don't know why but it
  seems to be the latest.  The keyboard part number is: 6611652; it is 
  listed on page 7.1.78 in the Apple Service Price Pages Book, dated
  January, 1994.  Note: all apple keyboards have the same part number
  so if you ask for a "rev D" the techie might not know what you want.
  The serial number ends in a D for the rev D.

ADB Port:

Problem:  While using an ADB device with a docked Duo the screen
freezes up.  The mouse and keyboard are unresponsive but, background
processes continue unabated (file transfers, calculations, screen
refreshes, modem downloads/uploads, etc.).

Solution:  Apple has incorporated the fix into a new system 
enabler - "Duo System Enabler" v1.0.  The new enabler replaces
the "System Enabler 201" that shipped with older Duo's.  Just
get a copy of the new enabler and toss it into your system 
folder (removing the old one to prevent confusion).  The 
new enabler became available on AppleLink 10/27/93.  Ftp info
in the "enabler" section below.

* comment: some people have reported conflicts with the enabler and
  the modem software 1.1.2.  See the "Enabler" section below


Problem:  You don't know which version of the enabler you should.
(There seems to be a problem involving the enabler 1.0, modem software
1.1.2 and the 210/230/250's that prevents your battery from charging
- even apple doesn't seem to be 100% sure what's going on here).

Solution:  The word from Apple is this: Everyone should use version 1.0
of the Duo enabler, not 201 or 201 v2.  Additionally, if you have a 210, 
230 or 250 you need a patch called duo battery patch.  If you have a 
270c you don't need the patch.  Future versions of the Duo enabler will 
incorporate the patch, so we won't need it then.  Many thanks to JC and 
Russ Emmons for the patch.  You can get the latest enabler and patch at
ftp.apple.com.  Locations:


Problem:  After you put your Duo to sleep, you hear a buzzing
coming from the back of the duo.

Solution: You don't have a problem.  This is normal for the Duo,
it's just the power manager recharging your battery.  The sound
has also been described as a "hum".

HD gone:

Problem:  Your Duo is fine by itself, but when you insert it
into a Dock with a hard disk, your powerbook Hard disk doesn't
appear.  Tools like SCSI probe find the Duo drive and can
mount it - it just won't appear on it's own.

Solution:  The problem is with some drivers.  Apple suggests 
reformatting the drive with version 7.2.2 of the SC HD Setup program, or 
a third party program (like APS Powertools).  A patch solution is to 
hold down the command key on startup (this forces the  computer to 
bypass the drive designated as the startup disk and startup off the 
other available drive).   

Missing Battery:

Problem:  Your Duo won't recognize the battery as being in -
even though you know it is.  

Solution:  First, make sure you've installed the battery
correctly (see above section on batteries) - your battery
might not be making contact with the battery leads.  If
you know you've installed it correctly, another possibility
is that the power manager needs to be reset.  To do this,
shutdown your duo and remove both the battery and AC adapter.
Then hold down the hardware reset button (on the back of 
the Duo - there's only one button so it's hard to miss) 
for about 5-10 seconds.  Insert the battery (make sure 
you do so correctly) and restart the computer.

Battery Leads:

Problem:  When you press on the left palm rest your Duo
crashes (acts like battery was disconnected).

Solution:  The problem seems to be the battery leads are bending
away from the battery.  When you press on the left palm rest
this warps the case around the battery just enough to break the
connection, and your portable suddenly doesn't have a battery
anymore.  Some people have reported success by using needle 
nosed plyers to bend the battery leads "just a little" to
make the connection to the battery a little firmer.
CAUTION!  These battery leads are just copper, if you twist them
too much you could break them - be *carefull*.

Stylewriter II

Problem: you have a stylewriter II and a duo with dock, but the
docked duo can't see/won't print to the stylewriter.

Solution: this is a hardware bug.  Bring your Dock into a techie,
tell him the problem, and let him know that your Dock needs to
have part #661-1657 (the docks logic board) replaced.  If you're
out of warranty, or just want to print now, one hack is to turn
off the printer, remove the duo, pull the printer cable out of the
dock, dock the duo, put the cable back in, and restart.

(this section under construction, information appreciated)


Sources: Where should I buy...?

   This section is a compiled list of a lot of phone numbers and addresses that
    people ask for.  I've made some recommendations and comments, please realize
    that these are subjective.  I'm recommending people who've done good by
    *me*, and who *IMHO* are the best sources.  I suggest you use this list as
    a jumping off point, but always keep an open mind.  In the end, the best
    guide you can follow is your own experience with each company.

Recommended for RAM:

  RAM prices change day to day - like commodities.  These are the folks I
   like to call when I'm buying RAM - I always call at *least* three places
   before buying - you can often shave $50-100 off the cost this way.  Just 
   cause one of 'em has the best price today, is no guarantee he'll have the
   best price tomorrow.

[King Memory, 1-800-255-4200, 714-380-9876  FAX 714-380-0995
  20 Fairbanks, Suite 171, Irvive CA, 92718]

[The Chip Merchant, 1-800-426-6375 (orders) 619-268-4774 (info)
  4870 Viewridge Ave, San Diego CA, 92123]

[The LLB Company Inc, 1-800-848-8967, 206-454-7258, FAX 206-454-7302
  300 120th Ave. NE, Bldg 1 Suite 120, Bellevue, WA 98005]


Recommnended for HD's:

  APS usually has competitive or the best prices on HD's and have the
   best tech support in the business (although MacWorld just gave 'em
   a "poor" rating on tech support - anyone know why?).  Anyway, for HD's
   they are my favorite - your mileage may vary.  LaCie is also an option,
   they're a front end for Quantum and have some pretty good bargins,
   I know nothing about their tech support but they have been around for
   a long time, and are not likely to run out on you.

[APS Technologies, 800-354-1213, FAX 816-483-3077, Intn'l 816-483-6100, 
  6131 Deramus, PO Box 4987, Kansas City, MO, 64120-0087]

[LaCie Limited, 1-800-999-1369, FAX 503-520-9100, Intn'l 503-520-9000]


Recommended for CPU's:

  If you're in school - check for a .edu sales deal, it's usually hard to
   beat.  When I was shopping for my Duo 230, I ended up finding it cheaper
   and getting it quicker by going to Bottom Line.  They sometimes have
   great prices, sometimes they suck.  You should always shop around, but
   I'd check out bottom line first.

[Bottom Line Distribution, 1-512-472-4956, FAX 1-512-476-6399
  1219 West 6th Street, Austin, TX 78703]


Clearing Houses:

  The following places are "I-want-it-now,-and-I-don't-care-how-much-it-
   costs" places.  They have just about everything, but the prices are
   *usually* ridiculous.  Ie $2.94 per MB HD's and $100 for a single 1 MB
   simm (these are real prices from their catalogs!).  You can often get
   software and cases and the like for a reasonable price, they're hard
   to beat for fast delivery, and they'll walk the most computer-phobic
   through whatever they have to offer.  The tech support is aimed for this
   market.  Bottom line: don't dismiss them, but do shop around, and if you
   can't get it anywhere else...

[MacWarehouse, 800-255-6227, FAX 908-905-9279
  1720 Oak St., PO Box 3013, Lakewood NJ, 08701-9917]

[MacConnection 800-800-2222  FAX 1-603-446-7791
  14 Mill Street, Marlow, NH 03456]

["MacZone", 800-248-0800, FAX 1-206-881-3421
  Multiple Zones International, 17411 NE Union Hill Road, Redmond, WA

[Mac's Place 1-800-814-0009  FAX  1-800-881-3090
  8461 154th Ave NE, Redmond, WA 98052-9917]



[Apple Catalogue (warning: highest-prices, if you're in school
  try to buy from your EDU source first!) 1-800-795-1000]

[Focus Enhancements 1-800-538-8865, 617-938-8088, FAX 617-938-7741
  800 West Cummings Park, Woburn MA, 01801-9640]

[RasterOps, 408-562-4200, FAX 408-562-4065, FaxBack 800-SAY-COLOR
  2500 Walsh Ave, Santa Clara, CA 95051 USA]

[Daystar Digital, 1-800-532-7858, 404-967-2077,  FAX 404-967-3018
  5556 Atlanta Highway, Flowery Beach, GA 30542]

[E-machines, 503-646-6699, FAX 503-641-0946, FaxBack 800-541-4787
  9305 SW Gemini Dr., OR 97005, USA]

[Safeware Insurance, 1-800-800-1492, Compuserve GO SAF
  2929 N. High St., PO Box 02211, Columbus OH 43202]

[Kensington 415-572-2700]

[Magenta Seven, Inc. 800-284-3957, CompuServe 75160,3030
  5109 Holly Ridge Drive, Suite 209, Raleigh NC, 27612-3146]

[Newer Technologies, 1-800-678-3726; 316-685-4904; FAX 316-685-9368
  7803 E. Osie, Suite 105, Wichita Kansas 67207]
[Computer Care, 612-371-0061, FAX 612-371-9342]


Places to Avoid:

   You tell me.  Post your horror stories to comp.sys.mac.portables, 
   I'll watch the debate and add only those places that the clear 
   majority agree are worthy of this honor.  (I'm a little nervous
   about this section, so I plan to err on the side of the companies.)


Opening Duo's: How do I install...?

Hardware upgrades on standard powerbooks are often easier than on
desktop models - this isn't true with Duo's.  Working on a Duo is a
b*tch. Details follow.

Ram Installation:

The one exception to this is ram upgrades.  You can add ram to
your duo easily, and without voiding your warranty.  Before you
do this you'll need two tools: a static ground and a torx-8 screw
driver.  Don't try this without both.

* Shut down the duo and remove the battery.

* Ground yourself with your static ground (the bracelet kind is the
    best).  Keep yourself grounded through the whole procedure, while
    it's unlikely you'll build up a static charge you could get one
    from the duo's plastic case and ram is *very* susceptible to static

* With the lid closed, turn your duo upside down.

* Remove the three torx screws on the bottom of the duo, under the
    keyboard (note there is no need to remove the fourth one, under the

* Open the Duo slowly (still upside down) - the keyboard will come
    free but will have a ribbon cable still attaching it to the inside
    of the duo.

* Holding the Keyboard, turn the Duo right side up, and careful set
    the keyboard aside (no need to disconnect the ribbon cable).

* The ram socket is in the lower right hand side of the recess that
    the keyboard was in.  Drop the ram in and slide it across till it
    snaps in place (this will be obvious - note there's a notch on the
    ram socket to prevent you from inserting the ram upside down).

* Replace the keyboard, close the lid, turn over the duo.

* Replace the screws.  Note if some of your keys don't respond well
    afterwards, you may have put the screws in too tight.  Just loosen
    them a little until they're in firm, but don't affect typing.

* Replace the battery, power up.  Check "about this Macintosh"
    under the apple menu to make sure the ram is added correctly.

* If your total ram is greater than 8 MB - you need to turn on 32
    bit addressing in the "memory" control panel and restart before
    your extra ram will all be available (if you don't the "about this
    Macintosh" will show your total ram correctly, but it will appear
    that all ram above 8 MB is being used by your system).

HD and Modem Installation:

Things to keep in mind: you will blow your warranty and it's very
easy to damage the soft molded plastic parts (Apple considers many
of these parts *disposable* in the process of opening the Duo). 
You're better off paying a pro $30 bucks to install these unless,
you're *very* hardware savvy.  I jacked in my own ram, but opted
for a tech installation of my modem and bigger HD - I recommend same.

A detailed description of how to open the Duo, is available via
ftp at sumex-aim.stanford.edu in the information directory, and the
second edition of the powerbook companion goes step by step through
the process - with pictures.

(this section under construction, more details will be included in
  future releases)


Not happy with your Duo?  As amazing a piece of workmanship as the Duo is,
some people always want more.  Here are the only upgrades I'm aware of.

Apples 2xx -> 250

Apple computers will upgrade your 210 or 230 to a 250.  What this boils 
down to is they'll add an active matrix screen.  The cost is roughly 
$1000, (not worth it to me).  Call 1-800-SOS-APPL to make arrangements 
for the upgrade.  Apple has recently discontinued the ->270c upgrade
I assume this one has also been discontinued.

Apples 2xx -> 270c

More interesting.  For only ~$2000 Apple will turn your 210 or 230 (it's 
not clear if they'll do this for a 250, but since the 250 and 270c were 
releasedat the same time...) into a 270c.  This boils down to getting an 
active matrixcolor display (16-bit!), FPU, and (if you had a 210) upping 
your clock speedto 33 MHz.  Tempting, but very expensive.  Call 1-800-
SOS-APPL to makearrangements.

Note:  This upgrade was discontinued as of 3/7/94.  

Apples Duo LC040 Upgrade

Apple is offering an upgrade of your Duo's logic board to the LC040 in
the 280 and 280c.  They're offering this for all Duo's and it costs
$2000.  Call 1-800-SOS-APPL to make arrangements for the upgrade.

Apples Duo Color Display Upgrade

You can have the same active matrix color display that comes in the 270c
and 280c for only $1000.  The display can switch between 256 colors at
480x640 resolution or one thousand colors at 400x640 resolution and is
offered for all Duos.  Note: it's unclear at this time whether older
Duo's will also require the logic board upgrade or if the 210/230/250 logic
boards will be able to drive this deeper display.

Apples 270c and up -> 290c

Rumor has it Apple will be offering PowerPC upgrades for 270c and higher
machines.  No details, or cost right now, and the guy who told me said:
"warn 'em: this is very much subject to change - no promises."

MacProducts 2xx -> 33 MHz/40 MHz

MacProducts USA will make your Duo faster.  They claim this is a logic 
board swap - but they're charging $299 and $399 respectively.  To be 
blunt: I don't believe 'em.  My guess is they're swapping the clock 
chip.  If you're resonably good with a soldering iron you could probably 
do this yourself.  The condition: the rest of the components on the 
board have to be able to take the higher level of performance.  Upping a 
210 to 33 MHz seems reasonable.  I don't know about the -> 40 MHz.  If 
you get any info, let me know.  

[MacProducts USA (800-622-3475)]

James MacPhails FPU upgrade

Miss your FPU while on the road?  A fellow named James MacPhail in 
Canada has figured out how to wire a FPU into a Duo 210, 230, or 250.For 
$295 (less $85 if you supply the correct FPU) he'll install it in your
Needless to say (but I will) this will void yourwarranty big time and 
*might* prevent you from upgrading the Duoto a 040 or PowerPC.  As 
another option, he'll install the FPU in a floppy adaptor ($340 included 
the floppy adaptor) - or attempt to do so in any mini/micro dock you 
supply.  I don't know James, but at least one person wrote me saying he 
did an excellant job.  As always, use caution when buying anything 
over the net - but James does sound like he knows what he's doing.  I'm 

[James MacPhail at jmacphai@cue.bc.ca]



As of today you only have one choice for an internal modem: the
Apple Express Modem.  (The Duo's serial will let you connect any
standard external modem.)  Note: make sure you read the part about
the serial port in part 1 of the FAQ - it has a lot to do with
the modem.

In mid-November of 1993 Global Village was expected to release a second 
Duo modem called the PowerPort Mercury - we're still waiting.  Recent 
news suggests  they've found a hardware bug and we can expect further 
delays.   This device will offer 19.2K (v.32terbo - a pseudo standard) 
raw  data transfer, v.42bis data compression, MNP 2-5 and 9,600 fax  
send and receive.  It will retail for about $400.  I've rec'd  
conflicting information about it using the CPU like the express modem or 
it being a standard modem. 

In a standard modem, the computer sends signals out to the modem,
which converts them to a form that can be transmitted over the
phone lines, and then the modem sends them on their way.  The process of 
translating this information occurs on the modems processor - not
the computers.  The express modem is different.  It is an adapter
for the computers motherboard, that lets the computer send signals
that are phone line compatible, so the process of converting the
signals occurs on the computers CPU.  The disadvantage of this is:
a) it's new technology, so has some bugs; b) since the translation
occurs on the motherboard, the modem processes (downloading in
the background for example) take up CPU time, slowing the computer
while you're trying to do other things at the same time.  The 
advantages are: since the CPU *is* your modem, you have a 
programmable modem - with future software you can upgrade your
transmission protocols (maybe v.fast?) or use your Duo as a telephone,
for example.

The current version of the express software is v1.1.2 (available via ftp 
from ftp.apple.com as dts/mac/sys.soft/7.system.updates/system 
-update-2-0-1-image.hqx).  Note the system update 201 is a lot more than 
just the modem upgrade, it also has updated hard disk tools and other 
machine specific updates.  Older versions than 1.0.4 of the express modem 
software should be replaced.  I suggest this because the older versions
have more incompatibilites and tie up more of your CPU time (causing
other applications to run slower).  

Global Village has released a commercial version of the Duo modem 
software.  The GV version of the software is reported to be much 
more effective in managing how much CPU time the modem takes up 
when not being actively used.  Your performance will be a maximum 
if you turn off your modem entirely when not in use.  Reports 
suggest that the GV software will also cause your mac to boot slower.
It does some kind of cataloging on restart that takes a couple of
minutes - I don't have details.

(this section under construction, all input appreciated)

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