Hi all,
I came by a load of cards for the Apple ii. I'm just working my way through them all and currently on this 128K clone.
Compared to another card online, there appears to be some components missing in the middle of the board, below the 6 resistors. I was wondering if these have been removed or were never there?
Also , the silk screen implies the memory chips are upside down, but other cards have them in this orientation as well. More an observation as the voltage rails seem to be correct on the "upside down" chips.The card doesn't work, but I found a dead 74LS93 on the board, so waiting for a new one. There was also a dead 4164, which I've replaced. The others are out of this board for testing just now, hence the empty slots.
The missing resistors etc certainly look to have been removed: you can see voids in the solder joints which were likely caused by pulling out the leads. Why I could not say. Maybe the card stopped working and was used as a parts donor.
Guess I need to find a schematic. Off a-hunting I will go!
Proving difficult to find a schematic for this Saturn 128K clone. Does anybody have some high res photos of either a clone or the real deal, so I can see what these components are and when they go?
Many thanks!
Perfect, thank you.
I'm going to assume the caps are 100nF like the rest of them on the board.