Re: HEXIO compatible to Elektor SC/MP system
I noticed that you do not use 2K2 pull up resistors on the outputs of the 74LS189, as shown in the original Elektor design. I don't get a ghosting problem on my LEDs using similar circuit to Elektor using 7489 chips with 2K2 pull ups on output. Though I didn't invert inputs and outputs, just buffered outputs with 7417.
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David
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