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Title: NeoGeo MVS-1A Board static RAM alternatives? Post by: DaMerl on May 24, 2012, 05:57:50 PM Hi Folks,
I've got a little problem with my MVS-Board: BACKUP RAM ERROR But the traces of the data in/outputs to the CPU are all okay. Now I want to replace both backup RAM's. The Sony CXK58257AM-10L are currently build in, but I know that there are technically the same but from Samsung KM62256C. But I'm sitting in Germany, and a good warehouse here in Germany is Reichelt Elektronik, and there I found the V62C518256 von Mosel Vitalic: http://www.reichelt.de/Drams-Srams/62256-70-M/3/index.html?;ACTION=3;LA=2;ARTICLE=40086;GROUPID=2954;artnr=62256-70+M;SID=12T76FJn8AAAIAAB0ENWsada44f607ed307e01ebb9af2371b75e6 But the RAM from Reichelt is faster in its access time: 70ns instead of 100ns like the others. Question: Is it possible to use the static RAM from Reichelt instead the other guys from Sony and Samsung? Thank you and best regards! Merl Title: Re: NeoGeo MVS-1A Board static RAM alternatives? Post by: channelmaniac on June 10, 2012, 07:46:50 PM 70ns isn't a problem as long as the pinout and functionality is the same.
However, Please post the error message. On the 1A if you have any battery leakage you'll usually end up with messed up connections to the /OE and /CE lines which will cause the error. Title: Re: NeoGeo MVS-1A Board static RAM alternatives? Post by: DaMerl on June 11, 2012, 11:41:19 AM Hi,
Thanks for reply. I replaced the RAM's already and the BACKUP RAM ERROR exists anymore. Therefore I got a new error: COLOR RAM BANK 0 ERROR Merl Title: Re: NeoGeo MVS-1A Board static RAM alternatives? Post by: channelmaniac on June 11, 2012, 06:36:18 PM That's a different error for a different set of RAMs.
Backup RAM is tested first... Pallette RAM last. Check the pair of CXK5864 chips. |