So you have no EPROM system at all ?

Are you sure the supply to the 373 is correct ? You definitely see ALE pulses on pin 11 ? Have you got the latch tri-state line set correctly ?

Is that weird DMA mode pin connected properly ???? You know, the one that guarantees no bus access while its asserted. Are you watching for signs of life AS you press the reset button. You only get a burst for a fraction of a second.

Its so long since I used it I forget the details !

Steve