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Q: Apple II Plus Memory Expansion

oldpcguy

Experienced Member
Joined
Sep 23, 2021
Messages
374
I have an Apple II Plus system which has a 16K memory expansion card. As is typical with this system the card is installed in slot 1 and has a ribbon cable which connects to bit one (D0, logic board position E3 according to the Apple II Refence Manual) of the third bank of memory. On this particular board the socket is white whereas all the other DRAM sockets are black. I suspect this was done to assist end users more easily distinguish where a memory expansion card should be connected.

While performing a basic memory test with my home-grown memory test program (which I type in by hand within the Monitor) it is indicating that bit 1 (i.e. D0) is stuck, always returning a one. I am wondering if this is a result of the memory expansion board being plugged into where a DRAM would normally be found (in a stock 48K Apple II Plus). Does anyone know? In order to test could I remove the memory card and install a DRAM chip into this socket? Or is my assumption that it's a normal DRAM socket not hold water?
 
UPDATE: The answer to my question is yes, you can install a DRAM into the socket and the system will return to 48K.
 
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