The early Mattel LED games Auto Race, Space Alert / Battlestar Galactica,
Football, Baseball and Gravity use Rockwell microcontrollers.

Interview with Mark Lesser says they are modified calculator chips.
Popular Electronics Jan 1978 says they are PPS-4/1.

Die shots of Rockwell calculator chips, Mattel game chips and PPS-4/1 chips
are very similar.

Lesser says that he only had 511 bytes for Auto Race.  The die has 512 bytes
and PPS-4/1 code must start with a Set Carry, Reset Carry or NOP.

Unisonic 21 blackjack calculator, Rockwell 63R calculator, Rockwell 64RD
calculator use A48xx chips.

Rockwell 8R calculator uses B5000 chip.  Rockwell 14RD-II calculator uses
B5901 chip.

Auto Race and BSG use B60xx chips; Football, Baseball, Gravity use B61xx.

MM75, MM76, MM77, MM78 in PPS-4/1 line are A75xx, A76xx, etc.  "A" prefix means
standard voltage (15 volts), "B" means low-power (6.5-11 volts).  Note that
MM75 and MM76 opcodes are different from MM77 and MM78, and that a LFSR is used
as the address counter.

US4339134 for blackjack calculator has schematics, block diagram, opcode
description and source code.  Chip is A4821, used in Unisonic 21 handheld and
desktop blackjack calculators.  Code transcribed as us4339134.bin.

US4162792 for Auto Race / Football mentions computer program listing included
in file wrapper.  I purchased file wrapper, but code is for a 6502-based
prototype.

US4322074 for Gravity has schematics and block diagram, and mentions object
code listing in file wrapper, so I purchased file wrapper.  Code is several
pages of binary, transcribed as us4322074bin.txt and us4322074.bin.

US4418917 for unknown Mattel game using same chip as Football has schematic.

I decapped Gravity and transcribed the bits as gravityraw.bin.  I was able to
reorder the bits to match object code.

I decapped Football and Baseball (transcribed as footballraw.bin and
baseballraw.bin) and reordered the bits in the same way (football.bin
and baseball.bin).  Note that the reordered dumps all start with $0C and byte
$20 (the next address in the LFSR sequence) is $1F for all 3 games.  PPS-4/1
chips and A4821 don't start at $00 after reset, though.  A4821 doesn't start
with Set Carry, Reset Carry or NOP.