[Coco] CoCo 2 64K upgrade blues

[Carlos Camacho]

>What does the machine being 'used' have to do with anything?

To avoid any sporadic reads or writes

>I suppose the best way would be to tie Pin 1 to the ground of the chip
which is pin >16. If you are saying that the machine runs ok with Pin 1
left floating but it does not
>when you tie it low that's kind of strange.

Yes, that is the situation. If I just install the RAM and do nothing, it
boots fine.
If I try any type of grounding on PIN 1, it won't boot. Take off the
grounding and it boots.

>If you haven't lifted the pins out of their sockets and are
>connecting them all to GND then you could be shorting out the whole system

It seems like the way you describe.

>If you haven't lifted the pins out of their sockets and are
>connecting them all to GND then you could be shorting out the whole system

After trying to ground PIN 1 two ways and not booting, and doing nothing
and it boots fine, what you are saying gels.

>Did you pull the pins 1 out of the socket before grounding?  If not I
suspect the
>problem isn't the grounding of pin 1 but the shorting of whatever signal
is on pin 1
>of the sockets to ground.

Aha.. interesting. I did not pull Pin 1 out of the socket. So you are
saying I should bend all the PIN 1s so they don't go into the sockets? If I
follow this advice, after bending PIN 1 out of the sockets, then the next
step is? Connect all the PIN 1s together and then go to ground? If so, what
is the recommended place on motherboard to ground to?

Thanks everyone for various advice. I haven't done a memory upgrade in 34
years. I find my lack of knowledge disturbing as Darth would say. ;-)

Carlos Camacho




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