After figuring out by myself that the Apple-1 needs additional power supply bypass capacitors to ever work reliably (in the sense of "rock solid"), which did cost me just a few months :-(Of course I had tried to find info on it when my build did not work, I did not find any, until I spotted this post by "wsander" here on Applefritter:
which appears to be a pretty complete solution as far as bypassing is concerned. But I wanted to do more perfect ;-) and made this:
You can see I use 10 different kinds of sockets with hidden components, mostly 100nF capacitors with one exception: the socket for the keyboard on location B4 has a 2K resistor from STROBE (pin 14) to GND (pin 9). The reason for this is that I use an 1990s subnotebook running DOS as keyboard which I don't trust to run unobserved due to age, so I like to unplug the keyboard cable and switch the notebook off while the Apple-1 build runs 24/7 with test programs. Having a PC faking the keyboard is really cool as it can also automatically "type in" said test programs once the DRAM works stable enough so as not to crash WOZMON all too often. Adding bypass capacitors is a necessary, but not sufficient condition to get a rock solid build. But this is another topic.
If there is enough interest from other builders lurking on this forum, I will spend some time to describe these sockets and where they go. I just don't want to waste my time on documenting things I found out nobody cares about, like my DRAM address line hammer program I published on this list.
As a proof, here is a photo of my most recent build based on a Newton NTI PCB which has NONE of the unsual 100nF bypass capacitor locations populated and still runs rock solid:
This means that the hidden capacitors can do a complete job in terms of power supply bypassing. This is cool because it enables us to use whatever value, style and color of bypass capacitors we can find or want to populate the usual bypass capacitor locations. Even 100pF would do as long as they have the desired looks ! This added degree of freedom should allow us to "cheat" a bit with the elusive capacitors used in the originals.
You also might note that this build only has 470uF electrolytic capacitors in lieu of the 2400uF/25V ones used in the originals. I proposed the use of the much safer and more abundant 2000uF/50V which I offer on Ebay but got a lot of sceptic messages saying they won't work. These fears are unfounded.Given enough interest, I can elaborate on that topic, too, and why using 25V types may be unsafe, but again, only if there is enough interest in such a discussion here on this forum.
Comments invited !