This article is from the Macintosh hardware FAQ, by Elliotte Rusty Harold firstname.lastname@example.org with numerous contributions by others.
This appendix is a nearly comprehensive list of the different species
of Apple Macintosh computers. At the top of each listing is the
common name of the model. Any aliases it may have, either common
nicknames or names under which Apple sold it in other markets follow
in parentheses, e.g., Mac 128 (Thin Mac). This is followed by
fourteen essential characteristics of the model which I'll elaborate
The first important feature is the processor in your computer, e.g.,
Processor: M68030 8 MHz, M68882 FPU
The first number is always the central processing unit (CPU). This is
the main brain of the computer and contributes more to the speed of
your Mac than any other single factor. M stands for Motorola and
means the chip is a member of the Motorola 68000 family. The other
possibility is PPC which means the chip is a member of the PowerPC
family from either Motorola, IBM or both. Generally within the same
family a higher chip number means a faster chip. A 68040 is faster
than a 68030 which is faster than a 68000. However Macs using the
same chip can run at different clock speeds measured in megahertz
(MHz). The higher the megahertz the faster the Mac. The clock
speeds I list here are rounded to the nearest whole number. More
precisely 8 MHz should be 7.83 MHz, 16 MHz should be 15.7 MHz and so
on. If a Mac has a floating point coprocessor (FPU) or digital
signal processor (DSP) that's listed here too. An FPU speeds up most
scientific, mathematical, photo retouching and ray tracing software.
Most other types of programs don't take advantage of it. A DSP is an
even faster FPU used to make real-time audio and video feasible.
M68040's and all PowerPC processors include integrated floating point
The second feature is the system software which will operate that
Mac. This is listed as a range of possible systems, e.g.
If any enablers are needed for a model, they're listed here too. Just
because a particular system will run on an Mac doesn't mean you
should use it. If you're using System 6, I recommend using 6.0.7 or
6.0.8 with the LaserWriter Driver 8.1, Quicktime and the Comm
Toolbox. Any version of System 7 that will boot your Mac will serve
equally well for most people, but you should make sure you have the
latest tuneups and enablers. (See the system faq for more details.)
The next field is RAM capacity, e.g.
RAM: 1-128 MB, 120 ns, 8 30 pin SIMM slots
For all but the earliest Macs this is given as a range from the least
amount of RAM Apple sold with the machine to the maximum amount it
can support with third party chips. RAM size is measured in
megabytes (MB). One megabyte is 1024 kilobytes which is 1024 bytes.
A byte represents one letter of text, so one megabyte is is about
three hundred pages of text. RAM speed is measured in nanoseconds
(ns), one billionths of a second. Smaller numbers are faster.
Finally I list the number of slots included for RAM (some of which
may already be filled in the default configuration) and the type of
memory that can be installed in these slots. For more details about
RAM configurations please refer to "Thanks for the Memory", section
4.0 of this document.
After RAM comes ROM, the non-volatile memory where much of the system
software is stored. This is listed as a size in either kilobytes or
megabytes since that's the only information that's commonly available
(and more than you really need to know anyway.) Larger ROMs tend to
be more recent and require less patching under newer systems. 512K
and larger ROMs are 32-bit clean. 256K and larger ROMs include Color
Ports are the holes on the back of the Mac into which something may
be plugged. ADB stands for Apple Desktop Bus. It's used for
plugging in mice, trackballs, keyboards, graphics tablets, and
obnoxious copy-protection dongles. ADB devices can be daisy-chained,
up to three devices per ADB port. Serial ports are used for modems,
printers, and LocalTalk networks. A SCSI (pronounced "Scuzzy") port
is mainly used for external storage devices like hard drives, tape
drives, and CD-ROMs; but there also printers, monitors, Ethernet
connectors, and scanners that can attach to the SCSI bus. Mac SCSI
ports are 25 pins. For more details see the SCSI section below.
Most Macs have at least one sound port for hooking up external
speakers and more recent Macs also have a sound in port for a
microphone. These are listed as either Mono in/out or Stereo in/out
depending on whether the Mac supports mono or stereo sound. Finally
if there's a port for an external floppy drive, that's indicated by
the word "floppy.".
The Floppy field specifies what kind of internal floppy drive the
model has, either 400K, 800K or SuperDrive. For more details see
section 6.0, Floppies, below.
Next I list the drive bays. Most Macs have exactly one bay for a 3.5
inch half-height device, almost always an internal hard drive. Some
more recent Macs also have room for a half-height, five and a quarter
inch, removable media drive such as a CD-ROM ar a tape backup system.
Slots are spaces inside the Mac for expansion cards of many kinds
including accelerators, extra serial ports, graphics cards, and more.
The most-common kinds of slots are Nubus and processor direct (PDS).
Nubus slots come in small (7") and full-size varieties while PDS
slots tend to be specific to the model. LC PDS cards do mostly work
in all LC slots, but even among Macs that have Nubus slots not all
cards work in all Macs, so it's best ask a vendor if their card works
in your Mac before buying.
Video specifies the characteristics of any built-in monitor and the
amount of VRAM for models that do not have a built-in monitor. See
section 6.0 on video to find out the resolutions and color depths a
given amount of VRAM supports. "None" means that you'll need to use
a graphics card as well as an external monitor.
Audio lists sample rates and bit depth supported by the CPU. If
there's a built-in speaker and/or microphone, this is mentioned as
well. Many Macs that don't have built-in stereo speakers or
microphones have jacks for external speakers or microphones. These
are listed under ports.
Network specifies the built-in networking capability of the Mac,
either LocalTalk or Ethernet. If Ethernet then the connector type is
also given. Third party cards and SCSI connectors provide options
for adding Ethernet to Macs that lack it.
Size specifies the linear dimensions of the model as height by width
by depth, then the approximate weight although this can vary
depending on the size of any internal drives and cards that may be
installed. This is the weight and size of the computer itself. It
includes the monitor and keyboard only if they're built-in to the
Mac. Finally I list the dates between which the model was sold and
any special features it may have.