Re: XT clone motherboard repair advice/help needed (KT 10 M/B)
Posted on 2019-04-17, 22:40
There is also another aspect, the fan-out problem. As the TTLs have quite low input resistance, they suck much current. And the TTL outputs can deliver only so much current until the signal gets out of the logic levels tolerances. Thus the chips have defined fan-in and fan-outs. Iirc a typical …