exxos's Atari, Amiga & retro forum

Kepler wrote: 06 Feb 2024 07:50 I have looked at the serial output and unfortunately it doesn't reveal anything other than "no chipmem detected".
I have since removed all 8 RAM ICs, soldered sockets and used 8 known working RAM ICs. However, that odd behavior on the HLT and RST lines has remained.

Hold down either left or right MB during boot. It will disable chipram test and let you get to the menu. Then do the chipram check. What does the OVL test right at the start say?

I have attached an image of the serial output.
I will try bypassing the chipmem test shortly.

In which case it's something Gary is relying upon that's the problem.

Seeing as you're having memory detection problems and Gary has a lot to do with the memory control this would suggest the problem is somewhere in Gary's vicinity, maybe the socket.

For a start check pins 20 and 21 (RAM enable and ROM enable) to see what they're doing, both on the PCB and on the chip leg.

Gary pin 20 RAMEN is constantly high on startup.
Gary pin 21 ROMEN seems to change between being high on startup or momentarily high and then go low.
That behavior is the same from the IC and board.

I don't think it's gary. looks like a ram issue. diagrom has checks for Gary

I can't seem to bypass the chipmem test by holding the mouse button down. Of course, I don't actually have any proof that the mouse functionality is working on the machine. I know the keyboard functionality doesn't work. The caps light doesn't come on nor does the keyboard reset work.