Re: Strange display problem Apple ][c

[Jan <jan.kronlund@ahlsellref.fi>]

Thanks for your help, I got one of my C�s working, after some heavy chip swapping
;-) . I was able to salvage enough good chips from the other two C�s to make one
OK. Now, since I want to get the other two working too, I�ll give a try on those
4164�s and I�ll keep you posted.
Thanks again,
Jan/Finland

Rubywand wrote:

> Jan writes ...
> >
> > I think that I have the problem solved, it is bad memory.
> > I will try replacing all chips with 4164�s since
> > no 4264�s are available here anymore, hope they work.
>  ....
>
>      Did some more checking on the 4264 (in a 1984 IC Master manual instead of
> ICM on-line). It turns out that this number has been used for a bunch of
> different parts by various manufacturers. (Not all that unusual. However, it is
> a bit of bad luck that the same number is used for two very different 64k
> DRAMs. Evidently, the Panasonic 4264 16k x 4 DRAM came after 1984.)
>
>      The only DRAM parts listed in the 1984 manual seem to be from Micron
> Technology. The MT4264-15A (150ns) and MT4264-20A (200ns) are 64k x 1 DRAM
> chips. So, if you have MT4264's in your //c, it looks like there is a pretty
> good chance the 4164's will work as substitutes.
>
> Rubywand