My recollection of the PB1400 when it was current that it was quite a slow machine.
Additional RAM was the way to improve things (if only slightly), or a G3 CPU which were pretty expensive at the time.
Memory for the 1400 is a bit of an oddball. There is a "factory" RAM socket and a "user" RAM socket.
The "user" RAM socket can actually have 2 RAM cards fitted, but depending on the combination of modules, you'll either hit the maximum RAM or the machine won't function. (See also
http://support.apple.com/kb/TA36087?viewlocale=en_US)
The only combinationd that gave the maximum of 64MB was (with 8MB on the logic board):
8MB in the factory slot
and
two stackable 24M modules in the "user" slot
OR:
8MB in the factory slot
and
one 48MB module in the "user" slot.
The problem we continually struck was customers who had previously purchased a 32MB module wanting to go to 64MB. Sadly, they had to replace their expensive 32MB module since it wasn't usable in ANY combination to get to the magic 64MB.
😡
NewerTech's old "
Guru v2.9" is a handy tool for determining what RAM works with many older Mac models
Also, some of the "user" modules weren't stackable.
😱
iFixIt has
a nice guide for accessing the RAM.
