zylon Posted January 6, 2010 Share Posted January 6, 2010 Turned on the "breadbox" 64 today and "out of memory" 0 free came up so it may have finally died. Now I'm on the backup 64C deck which I've made from 2 64's and a vic-20. Ugly but functional. Tried the piggyback method on the ram chips with no luck. Can't tell if the spares are good either. Quote Link to comment Share on other sites More sharing options...
jkonstan Posted January 6, 2010 Share Posted January 6, 2010 (edited) It sounds like the 64K x 1 DRAMS on your C64 motherboard have gone bad. The DRAMs can be damaged by a bad C64 Power Pac (excess ripple on the +5 Volt output). I would change all 8 of the 64K x 1 DRAMS and test your +5 volt output on the C64 Power Pac for excess ripple. Turned on the "breadbox" 64 today and "out of memory" 0 free came up so it may have finally died. Now I'm on the backup 64C deck which I've made from 2 64's and a vic-20. Ugly but functional. Tried the piggyback method on the ram chips with no luck. Can't tell if the spares are good either. Edited January 6, 2010 by jkonstan Quote Link to comment Share on other sites More sharing options...
zylon Posted January 6, 2010 Author Share Posted January 6, 2010 (edited) Mine uses 8 4264-20's. Anyone know a good vendor to buy these from? The deck's in great shape and may be worth saving. As a precaution, I'm using the 64c's supply just in case the other is dying. Edited January 6, 2010 by zylon Quote Link to comment Share on other sites More sharing options...
jkonstan Posted January 7, 2010 Share Posted January 7, 2010 You can buy the 64K x 1 DRAMs at Jameco Electronics ($.99/DRAM). You can use 120nsec, 150nsec, or 200nsec DRAMs in the C64. http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=41662 Mine uses 8 4264-20's. Anyone know a good vendor to buy these from? The deck's in great shape and may be worth saving. As a precaution, I'm using the 64c's supply just in case the other is dying. Quote Link to comment Share on other sites More sharing options...
zylon Posted January 7, 2010 Author Share Posted January 7, 2010 (edited) Thanks for the link. I just ordered some. I see the logic in chamging all 8 instead of 1 or 2. The weakest one fails first, meaning the others aren't far behind. Looking at mine, I see one chip is different than the others. Leads me to believe I'm not the first to repair this machine. I'm also going to use sockets this time. Edited January 7, 2010 by zylon Quote Link to comment Share on other sites More sharing options...
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