On Fri, Sep 16, 2016 at 5:41 PM, Chuck Guzis <ccl...@sydex.com> wrote: > The TMS9900 has already been identified as a 16-bit ISA, even with its > bit-serial ALU.
I don't know what the width of the TMS9900 ALU is, but I'm pretty sure it's not bit-serial, as an add instruction only takes 14 clock cycles, including four memory cycles. I'd be very surprised if the ALU isn't either 8 or 16 bits, though 4 might be possible. Possibly someone is confused by the bit-serial "CRU' I/O space, but that is unrelated to the ALU width.
