Logic Analyzer probe loading seems to fix boot issue

While I had my logic analyzer connected to my memory card tonight, I noticed that I no longer had the white screen hang on bootup problem that I’ve been plagued with since this card came in.

As a matter of fact, it was booting up about 100% of the time.

I disconnected my HP logic analyzer probes, and all of a sudden, the Amiga won’t boot any longer.

It seems as if the impedance loading of the probes have been POSITIVELY affecting my circuit….slowing down the rise times and fixing whatever issue was in place.

The address pins and a single ground connection must be left attached to my turned off logic analyzer in order for this card to allow the Amiga to boot normally and properly detect the memory.

I’ve also read previously that it’s possible to have too fast rise times for older legacy hardware, and perhaps the choice to “upgrade” to 74ACT last minute has shot myself in the foot.  I do have some 74LS components ordered for exactly this emergency, but time will tell.

 

About the author

keith

Amateur Electronics Design Engineer and Hacker