Re: Millipede to JAMMA? Anyone?

BINGO! The missing piece of the puzzle! I knew that the 22 + / - were
for the EEProms and high score save (and that it should boot without it)
But I did not know that the +22 also ran the single transistor video
amplifier!... I hooked pin 3 to +12, and bypass jumped the 7815 and its
all better! Thanks guys! and happy thanksgiving!

-=Mark=-
solarfox@texas.net wrote:

>On Wed, 23 Nov 2005 18:55:42 +0300, you wrote:
>
>
>
>>>I do have the resets hooked up as required, so Im a bit confused as to
>>>why its not working :-(
>>>
>>>
>
>
>
>>2 - millipede uses an eerom, so it probably needs 12v connected to some 14.5v
>>transformer input or something - check the schematics. i had this problem
>>starting a starwars on the scope so it's probably the same.
>>
>>
>
> Millipede requires the +22Vdc and -22Vdc supply rails from the ARII
>board in order to generate the -28Vdc programming voltage for the EAROM...
>but unless I'm missing something in the ER2055 EAROM's data sheet, all that
>will happen if the ER2055's negative VEE supply is absent is that the
>ER2055 can't successfully do a write cycle. The board should still boot
>without the +22V/-22V supplies; it just won't save high scores.
>
> However -- looking at the Millipede schematics, I see two things you
>should check:
>
>(1) The board will not come out of power-on reset until it gets the 10.6Vdc
>(unregulated) voltage from the power supply. Do you have anything tied to
>pin "E" and pin 18 on the Millipede board? If not, try connecting it to
>+12Vdc from the JAMMA harness. (Since the original voltage supply was
>unregulated, and the TL082 op-amp driven by it is rated for supply voltages
>up to 36V, the board shouldn't have a problem with getting a regulated +12V
>on that line.)
>
>(2) The +22Vdc supply is _required_ for the video outputs to work, because
>the final output stage of each color is a single-transistor amplifier that
>runs off the +15V which Millipede derives from the +22V input. (The +22V
>goes through an LM7815 regulator, so just hooking +12V to pin 3 on the
>Millipede board won't be good enough; the input voltage to an LM78-series
>regulator needs to be at least 1.5V higher than the rated output voltage,
>if memory serves.)
>
>
>-----------------------------------------------------------------------------
>"There is no virtue in suffering fools gladly, for it only encourages them to
>persist in their foolishness." --Kehlog Albran
>-----------------------------------------------------------------------------
>solarfox@DON'TMESSWITHtexas.net (Gary Akins jr.)
>http://lonestar.texas.net/~solarfox
>-----------------------------------------------------------------------------
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Received on Thu Nov 24 14:51:45 2005