1) PDS memory cards are compatible with third-party RAM Slot memory
cards. PDS cards do not use the Apple Memory Decode Chip, so there are
no compatibility problems. Any third-party card designed for the new
Macintosh Portable should work. Contact the card's manufacturer for
compatibility information before buying.
The only memory card affected by the memory decode chip problem is
Apple's. When an Apple 1MB or 3MB PSRAM Memory Board is installed, you
cannot use the PDS for RAM expansion. The Apple card will try to
decode memory accesses above the 4MB boundary.
2) The pseudo static RAM of the upgraded Macintosh Portable requires a
refresh line. SRAM cards designed for the original Macintosh Portable
will not work with the new Macintosh Portable.
3) The Backlit Upgrade consists of a new bezel (including display) and
a card that goes into the ROM slot that powers the backlit display.
PDS cards and RAM from the original system will work in the upgraded
system.
4) For the new Macintosh Portable, the RAM slot can support up to 3MB
of PSRAM, with 1MB soldered on to the main logic board. The PDS card
can support up to 7MB of RAM (provided the Apple Memory Card is not
used) making for a grand total of 8MB for the system.