Are you referring to the CIX?
Unlikely. The FIX is the exchange for US federal agency networks.
There are two, FIX-EAST and FIX-WEST. They predate the MAE's and
are, coincidentaly are where the two most popular maes flourished,
mae-east is housed where FIX-EAST was born and FIX-WEST is in the
same location where MAE-WEST started.
The predecessor of FIX East (FEBA was in the SURAnet machine room in
the basement of the CSC Building on the campus of the University of Maryland
in College Park, where we had an NSS, and a NASA Proteon P4200 and an
ESnet cisco AGS were connected. These networks peered with each other and
SURAnet (using EGP and various crufty configurations - this was put
together throughout the spring of 1990. In the summer of 1990 we moved off
campus because there was no space left (for people, equipment, or new
circuits). In the new machine room out on Baltimore Blvd, a Milnet cisco
and a TWBnet
Butterfly were added. Also sometime during this period, I can't remember
when exactly, UUnet/Alternet stopped appearing as a subscriber to SURAnet
and started peering with us and the NSS (early peering vs transit wars).
Although the NSS is gone now, and I expect that TWBnet is, too, at least
some of this stuff still probably peers out there but I haven't been
there for a couple of years now so I'm not sure....