The 68000 has a 16 bit data bus.
(I always assumed it's 16 bit internally as well? Longword unary register operations take slightly longer than their word equivalents, even though the instruction is the same size in both cases.)
(I always assumed it's 16 bit internally as well? Longword unary register operations take slightly longer than their word equivalents, even though the instruction is the same size in both cases.)
Correct, it's mostly 16-bit internally. Registers are 32-bit, but are split into 16-bit halves. The ALU is mostly 16-bit, but has a 32-bit shift register which is used for both shift/rotate operations and multiply/divide. There's a 32-bit adder in the "address unit" that's used for effective address calculations (including the LEA instruction), but it's much more limited than the ALU