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yeah, it's 2 4-bi RAMS uPD444c i think that's a rare one.<br>
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Mark<br>
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Byron G. Jacquot wrote:<br>
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<pre wrap="">I am working on this TB-303 that has a wierd issue. When I go into
proram mode I can play any note from the keys, but when I play back
from the memory, every note is one of the lowest 4 on the keyboard.
Also slides and accents don't record, but octave up and down do.
Is there a bad memory chip? Has anyone had this problem? I have been
running over and over it all day.
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That's an 8-bit RAM chip, right? Check the data outputs from it with
a scope probe, while playing back. You might also watch the !RE
line(s) to it, as well as the address lines.
If it's two 4-bit RAMs, then there may be a problem in decoding the
even/odd addresses, or one of the chips has gone bad.
IF it's like the TR606, with 2 4-bitters, you could try swapping the
RAMs with each other and see if the problem moves with 'em.
Byron Jacquot
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