I am also the proud owner of a Mattel Battelstar
Galatica anno 1979 week 14.
The chip used in this vintage handheld game is labeled B6001EA
and I guess it's a Rockwell International PPS-4/1 micro controller
(a PPS-4 cpu with clock, ram and rom) from sources I found on the net.
Many of the Mattel games of that era were variants on Rockwell calculator chips.
Not unrelated to 4-bit general purpose CPU's of the era, but the game chips were
way closer to the calculator chips.
Read the interview with the game's designer, Mark Lesser:
http://www.digitpress.com/library/interviews/interview_mark_lesser.html
Tim.