IIgs Rom3 Sequential Systems Ram Card?

["ed_jeffre" <ed_jeffre@ims.msn.com>]

I have a IIgs Rom3 computer with 2mb Ram.  It has a ram expansion card.  The
card is 1MB (I think) and has 2 banks of chips soldered to the top 2 banks
(8 chips each #NEC D421001V-10) and has no chips in the lower 2 banks
(Plug-In).  The markings on the card Chip side are a triangular logo and the
number 0693 under it.  Silkscreened on the back is Copyright 1991 Sequential
Systems Inc. Rev 1.  Can anyone identify this card for me?  What chips are
used to expand it to max?  What is max?  Theres a jumper near the blade end
of the card, what's this for?
Appreciate any help.
ed_jeffre@fuse.net