Worth noting that the Apple ][ and C64 had a 1.023MHz clock rate with a minimum of 2 cycles per instruction, so your “horribly slow” system might be about real-time for the era.
(Atari 800 had a 1.77 or 1.79MHz clock, but wasn’t regarded as wildly different.)
(Atari 800 had a 1.77 or 1.79MHz clock, but wasn’t regarded as wildly different.)