On 2013-06-30, at 12:11, silverdr@wfmh.org.pl wrote: >>>>> If I was using it in a VIC-20 as RAM >>>>> expansion, then I would connect it to PHI2, knowing that nothing >>>>> will access it at the moment PH2 = (L). >> >> http://www.d81.de/CLD-RAMBOard/RAMBOard-2C.shtml > > According to the doc and schematic above, _RFSH is as your overgeared brain-cell suggested :-) to be connected to PHI2 and one more cap for delaying the _OE/_CE lines should be added. I did so and it still doesn't work. I even connected CS to PHI2 as in the schematic, although I don't think it to make a difference. And it didn't. Eh.. Will have to wait for more time.. http://www.smspower.org/uploads/Development/SegaMasterSystemIIServiceManual-1715922A-1.png This seems to be official schematic from SEGA, which uses the same chip and they do what I did in the first try - connect both CS and _RFSH to VCC.. None of the combinations seem to work for me but I found something that /might/ be the reason... http://dl.dropboxusercontent.com/u/58002657/4168_notes.jpg Note 2. This still does not explain why both (especially SEGA!) of the above circuits supposedly work.. but if they do access the RAM as part of POST, they at least to some _CE toggles. -- SD! Message was sent through the cbm-hackers mailing listReceived on 2013-07-12 15:00:04
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