I agree with Pwillard.
You could use one or two 74ls193 4 bit up down counters and use the 74154 as a de-multiplexer. A few NAND Gates (7400) to toggle which one is counting and thats that.
I agree with Pwillard.
You could use one or two 74ls193 4 bit up down counters and use the 74154 as a de-multiplexer. A few NAND Gates (7400) to toggle which one is counting and thats that.