I still have my Mac Portable - it still works and was in daily use
until only a few years ago.
The Mac Portable was supplied in a large, black, padded "suitcase"
for lugging it around. The original Portable with the non-backlit
display used static RAM. This rendered memory upgrades extortionately
expensive. The later backlit models used pseudo static RAM, as did
the early PowerBook series machines. The use of static / pseudo static
RAM meant that the computer could be put into a "sleep"
mode with all applications running. Waking it from sleep took only
a fraction of a second.
Also, RAM could be set aside as a "RAM Disk" that could
even be booted from, thus greatly extending battery life. The RAM
disk would appear on the desktop as a floppy disk with an icon of
a "chip" in it. Battery life for the original Portable was
around 6-12 hours. In the later backlit models, this was reduced to
3-6 hours due to the display backlight and the cheaper pseudo-static
RAM.
The later PowerBook 100 computer was basically a Mac
Portable in notebook format, assembled (I think) by Sony.
From memory, the Portable continued the tradition of earlier Macs
in having the signatures of the design team moulded in to the plastic
inside the case.
There were some strange quirks to the SCSI port on the Mac Portable
- it didn't supply "termination power" to the bus, and did
not have proper internal termination. If you wanted to add more than
one external device, two SCSI terminators were required.
The built in trackball and keyboard could have their positions swapped
for the benefit of left handed users. A small 9v battery provided
backup power for times when the main battery was being swapped out
for a spare.
The power adaptor for the Mac Portable was functionally identical
to the power supply for the early PowerBook computers. The computer
relied on the battery being present to supply enough power to start
up the 3.5" 1/3 height hard drive. If the main battery was not
present, or was exhausted, the power adaptor alone could not boot
the computer.
Apple made a special "low power" version of
the ADB mouse for the Portable. This appeared identical to the normal
ADB mouse, but had a small "low power" icon on the bottom.
In time, the "normal" mouse was dropped from the range and
they all became "low power".
The pictures on your site all show a Mac Portable with
the standard trackball removed and the optional numeric keypad fitted.