intric8 wrote:This leaves me with a few questions.
1. Should I de-solder the plugged holes and solder in a socket for a function ROM? I wouldn't ever want to solder in a function ROM as there'd be no way to disable it. If I installed a socket for a function ROM, would I need to remove a section of the heat shield for it to fit?
2. And look at that area above the ROM bay. It looks like it's made for a jumper - for adding an on/off switch, perhaps? Does anyone reading this know if that's for enabling/disabling the function ROM when it is installed?
I found the schematics if you're skilled in reading those.
Hi, I may be able to shed a bit of light on question 2 here:
If the jumper area you are referring to is the one labeled J2, then it is not for enabling/disabling the ROM, but for selecting the size, either 16Kbyte or 32K.
I'm afraid that in order to be able to disable the ROM, it is necessary to cut the trace on the board that connects /CE (Chip Enable) to ground, and install a switch there so that this pin can either be grounded or pulled up to Vcc (5V) via a resistor, as I have shown in this excerpt from the diagram: