[vcf-midatlantic] FS: Central Data Corp 64K Dynamic RAM S-100 Board TESTED/WORKING

Systems Glitch systems.glitch at gmail.com
Tue Sep 6 12:36:24 EDT 2016


link: http://www.ebay.com/itm/272366924496

Just finished repairing and testing this one. There was a bad 74LS156 in the address decode section, which was replaced with a ceramic mil-spec device. The board is fully populated with nice gold capped purple ceramic 4116 DRAMs. The board provides for disabling 16K segments or 2K blocks within a segment to fit around ROM monitors and such -- it's currently set to leave a 4K hole from 0xD000 - 0xDFFF for my Dajen SCI's monitor.

It'll work with a front panel, but I don't recommend it for front panel operation. Like many DRAM boards, you can deposit data just fine, but the data lights will show incorrect information until you EXAMINE the location again. It's frustrating to work with. Probably fine if you just use the front panel for debugging or to start the machine. 

Thanks,
Jonathan



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