Bob,

Thanks for the reply. I found the 64 pin "shrink dip" sockets from
Digikey part number ED22647-ND. Thanks also for the tips on this CPU.
I have a working version of this synth I can compare with. I'm a bit
leery of possibly hurting the good one but so far I took all the
floppy controller and memory chips and transferred them to the unit
that did not originally have a floppy drive and I got that to work
properly. I installed sockets to make it easier. I'm also looking to
find a WD1772PH-02 floppy controller from an Atari. Fun, fun, fun.

Fran

--- In chipdir-l@yahoogroups.com, Bob Paddock <bob.paddock@...> wrote:
>
> On Saturday 26 January 2008 01:26:30 pm narfman96 wrote:
>
> > I'm looking for a HD63B03YP Hitachi CPU in a 64 pin dip package.
This
> > is in a Yamaha DX7IIFD synthesizer and will not boot. I see that
pin 15
> > is not producing a reliable 500khz clock output. The waveform is
noisy
> > or never gets produced at all. Is there a more common sub for
this CPU?
> >
> > Also has anyone seen a 64 pin dip socket for these? It is a high
> > density style which has the pins a lot closer together than a
standard
> > dip.
>
> I had some of those chips long ago, not that really helps now,
> but there are sockets. They are at a 0.07 inch pitch rather
> than the common .1 inch pitch.
>
> Check the rest circuit, which might control some mode select pins.
> These chips had a tendency to be flaky if reset was not clean.
> Also worth checking the oscillator sections for capacitors that
> have gone bad over the years. Both of those will lead to
> symptoms like you are seeing.
>
> --
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> http://www.softwaresafety.net/ http://www.designer-iii.com/
> http://www.unusualresearch.com/
>