Changing between 40007/8 and 40010 Gate Arrays

[balford]

Hi folks,


I have a CPC 464 board with a dead 40010, that has provision for the earlier 40007/8 GA (Z70200, MC0002D). I've sourced a 40008 to replace it, but there seems to be no clear guide about how to go about this.


I did find a post from Spirantho a while back about going in the other direction, and using this in conjunction with the service manual came up with the following:


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Convert from 40007/8 -> 40010:
Remove R138 and R139
Change R136, R128, R120 to 270R
Change R134 to 180R
Change R145 to 56R
Remove capacitor and add wire link at C132 if present


Convert from 40010 -> 40007/8:
Add 12R 1/2W resistors at R138/R139, use shroud or heatshrink to insulate
Change R136 and R128 to 220R
Change R120 to 10K
Change R134 to 100R
Change R145 to 1K
Remove wire link and add capacitor (value?) at C132 if present
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Can anyone confirm my thoughts? The last line I'm particularly curious about - on my board, the C132 position exists but has a trace going between the pads, and is not labelled. Do I need to cut this trace and if so, what value capacitor is required?

Thanks in advance!