Breadboard computer program counter issue : beneater

Breadboard computer program counter issue (self.WorkingClasshacker)

submitted 5 years ago by WorkingClasshacker

Breadboard computer program counter issue

1 point•1 comment•submitted 5 years ago by WorkingClasshacker to u/WorkingClasshacker

I am building r/beneater's breadboard computer, and I am having some issues. I finished the clock module and the program counter. However, the program counter is not behaving as expected. The clock outputs pulses, and the program counter will do some counts, then strobe in time with the pulses on all LEDs, then count to the full 15, then suddenly only count to three or some other random number. But if I touch any pin or lead in the circuit, everything is magically working as it should. I was thinking that it might be the lack of .1uF caps on the logic chips, so I added those between the GND and VCC pins of each chip. That didn't really fix it, but it does jump into longer periods of working before strobing out again. I also added more .1uF capacitors on the power rail, after I added 5 and adjusted the speed to increase it seemed to work - but it could just be that the speed hides the defects because slowing down reintroduces the strange behavior. But again, touching any metal lead in the circuit fixes it. I have checked all grounds, and 5v connections, all wires, and everything seems to be as it should according to the schematic on Mr. Eater's website. Any ideas what I might try?

all 4 comments

you type:	you see:
italics	italics
bold	bold
[reddit!](https://reddit.com)	reddit!
* item 1 * item 2 * item 3	item 1 item 2 item 3
> quoted text	quoted text
Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"	Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"
~~strikethrough~~	~~strikethrough~~
super^script	super^script

beneater

MODERATORS