System 1 Help Needed

OU Flight

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When I go into test mode I am getting a RAM ERROR AT: A01462 message. I have been looking at the manuals and can't figure out how to tell wich chip to inspect.

The game (Road Runner) also stopped playing sound and not coining up. I don't know if these are related to the RAM error, but I figured I would start there.

Thanks for the help
 
This is probably dumb but have you considered looking at the chips' labels to see if that particular RAM is labeled with a sticker?
 
Yeah, I can't find any numbers on the chips that match these. The manual says to reference a memory map/schematic but I still can't figure out how to tell where this chip is.
 
That's no chip number, it's a memory address.
Ref. the game manual (TM-285, 1st Printing), Chapter 2 (Self Test), page 2-2, in the right column, half-way down:

"If the RAM test fails, the error messages appear as shown in Figure 2-2. Refer to the memory maps and schematic diagrams in the schematic package supplements for this manual and for the System 1 Operators Manual to determine the location of the faulty RAM circuit."

The System 1 Operators Manual is the 1st one on the list here: http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/System_1/

Sheet 3B has the memory map. Your error address, 0xA01462, would appear to fall within the "Playfield RAM"...

Unfortunately, after that it get's a little more difficult. (Atari's documentation quality dropped steadily after the mid- to late-70s.) I'll have a look at the address decoding circuitry and see if I can puzzle which RAM IC that address fall in...
 
Thanks so much for looking into it for me. I found the first part in the manual where it just said to reference the other manuals and didnt know where to go from there.
 
I wish I coulda taken you all the way home, and identified the IC location. But 16-bit hardware really stretches my limited skillz. I'm much more at home in the 8-bit world.

I looked over the schems a bit, but was only able to narrow if down to a bank of 8 RAMs (and I was only about 80% certain of even that...). I wasn't able to follow all of the address decoding... Perhaps there's a REAL System I expert around who can chime in.

[Or you could shotgun every RAM until it's fixed... That's what I ended up doing on an Ikari Warriors a few years back; eventually did fix it.]
 
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