Hi all,
Emboldened by the realization that APF graced the Imagination Machine with socketed chips, I've decided to try and get mine working. Currently, the M-1000 console is fully functional, and when I plug in my RAM cartridge I can see the title screen no problem. However, upon boot up, I'm presented with a screen full of @ symbols and then it restarts.
I suspect a RAM issue, and am hoping to identify the bad chip and replace it. However, it looks like the 4108 chips used in the Imagination Machine are no longer readily available. Is there a substitute?
Additionally, while I've done some repairs before, I've never quite understood how to identify a bad RAM chip. I've got a test probe, and I've successfully used it with guidance, but is there a trick to being able to tell which pins should be high, low or pulsing? is it literally just a matter of identifying where the power is coming in and out, checking that those are high, and then identifying the data lines and ensuring those are pulsing? Could I use a chip data sheet to tell me which pins should be doing what? Or am I completely off the mark?
Emboldened by the realization that APF graced the Imagination Machine with socketed chips, I've decided to try and get mine working. Currently, the M-1000 console is fully functional, and when I plug in my RAM cartridge I can see the title screen no problem. However, upon boot up, I'm presented with a screen full of @ symbols and then it restarts.
I suspect a RAM issue, and am hoping to identify the bad chip and replace it. However, it looks like the 4108 chips used in the Imagination Machine are no longer readily available. Is there a substitute?
Additionally, while I've done some repairs before, I've never quite understood how to identify a bad RAM chip. I've got a test probe, and I've successfully used it with guidance, but is there a trick to being able to tell which pins should be high, low or pulsing? is it literally just a matter of identifying where the power is coming in and out, checking that those are high, and then identifying the data lines and ensuring those are pulsing? Could I use a chip data sheet to tell me which pins should be doing what? Or am I completely off the mark?