On 05/14/2012 07:37 AM, Gerrit Heitsch wrote: > > Like here: > > http://www.ebay.de/itm/290695335618 > > From what I found via Google, the UL224D is a CMOS-Version of the 2114 > made by ZMD in the GDR when it still existed. Since I wanted to find out, I ordered 5 of them and got them today. The good news, they are 2114 compatible. The bad news is that they are labeled 300ns but must be slower since a 2114-3 does work. I can access them from the CPU just fine (read and write), but VIC reads garbage. The only explanation I have is the 74LS373 demultiplexer using RAS which goes LOW about 150ns after PHI0 goes low. If the addresses supplied by VIC are also 150ns or so late, this might explain why the CPU can read the RAM while VIC can't. They might work in a VIC-20 though. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2012-05-15 22:00:14
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