testing AR2 - rev04 question

joeycuda

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I have a couple of AR2 rev 04 boards, never rebuilt. Knowing that Centipede requires the rev 02, I thought I'd try testing them in the Centipede. For both, same result - game seems to play fine, but no audio.

Looking at : http://www.elektronforge.com/AudioRegs.htm

I see that compared to the 02, the 04 is missing the +12vdc and -5vdc, but both have "audio". Is that correct that the audio should NOT work in Centipede with the rev 04? That's my assumption that it's the +12 or -5 preventing that.

Thanks in advance..
 
Correct. The +12V and -5V drive the op-amps for the audio circuit. IIRC everything else should work fine.
 
Cool, thanks.... I dug and dug and saw the lists which told what game, but couldn't determine that.

The answer is found in the 4 most fundamental, and important, documents about Centipede:
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Centipede/Centipede_DP-182-5th-01A.pdf
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Centipede/Centipede_DP-182-5th-01B.pdf
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Centipede/Centipede_DP-182-5th-02A.pdf
http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Centipede/Centipede_DP-182-5th-02B.pdf

It does look like -5 and +12 are only used in the audio output.

You can also verify that the ARII-04 boards' +22 and -22 lines work: they are used on the PCB to generate +/-15 (which are in turn used to generate -28) to operate the EEPROM for high score saving. So if HS saving (of the top 3, I think) works, then your +/-22 supply is good. (Of course, can't be sure about the audio amps on the ARII, as the PCB isn't generating any output).

Oh, I should clarify, just remembering the high-scores doesn't mean the +/-22 is working. It's only required to write/change the HS data. So you'll need to set a new HS and see if that saves properly (through a power cycle)

... or just get a multimeter and verify the output voltages.
 
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