Williams / Motorola logo
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Probably because an M is like an upside down W 
Similar, but subtly different.
I think the WPC processor was a Motorola!
EDIT: it was...
http://bcd.github.io/freewpc/The-WPC-Hardware.html
The CPU board contains the main processor: a Motorola 68B09E, running at 2Mhz. It is an 8-bit/16-bit CPU with a 64KB address space. Bank switching is required to address more than 64KB. On reset, location 0xFFFE is read to determine the address of the first instruction.
8KB of RAM is located at physical address 0x0000. When power is turned off, three AA batteries on the CPU board maintain the state of the RAM.
The game ROM size varies from 128KB to 1MB, depending on the game. The hardware supports a maximum of 1MB; this upper limit was used in all of the later models to accommodate more and more graphics. The uppermost 32KB is permanently mapped into the 64KB address space at address 0x8000 and contains the core operating system functions. The remaining parts of the ROM must be bank switched in, 16KB at a time; only one 16KB bank at a time is visible at address 0x4000.
The WPC ASIC is the heart of the system and is essentially a giant address decoder. It combines a lot of the functionality that was performed by PIAs and TTL logic in earlier solid state games. All read/write requests from the CPU are first seen by the ASIC, which can then either respond to it directly if it is an internal function, or forward the request to another device. RAM and ROM requests cause those devices enables to be asserted. For I/O, it may be more complicated and cause I/O to other circuit boards.
