How do I add an external reset line to a socketed CPU ?

Thread Starter

mpownby

Joined Oct 7, 2016
12
I've got an Apple IIgs computer with a 65C816 CPU inside it. It appears to be installed on the motherboard in a socket like this: https://www.digikey.com/product-detail/en/assmann-wsw-components/A-40-LC-TT/AE10008-ND/821762

I want to add an external line going to pin 40 (the RESET' pin) of this CPU so that I can reset the CPU externally and perhaps share my solution with others in the future. I've made a few PCBs in my time, so I am thinking about making a little PCB to do this and have the CPU plug into my PCB and have my PCB plug into the motherboard's CPU socket. The problem is, what part do I solder onto the bottom of my PCB so that it plugs into the existing socket on the motherboard? It seems like a lot of people advocate just desoldering the old socket and soldering in something like this ( https://www.digikey.com/product-detail/en/assmann-wsw-components/AR-40-HZL-TT/AE10018-ND/821772 ) but I figure there has got to be a solution that uses the existing socket.

Thanks in advance!
 

MrChips

Joined Oct 2, 2009
25,040
You don't have to remove the 65SC816 CPU chip.
/RESET is connected to many other ICs on the Apple IIgs. Find the circuit schematic and trace the PCB to locate the most convenient place to put a reset connection.
 
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