home .. forth .. misc mail list archive ..

Backwards MuP21 chip


With all of the headache I've been giving myself trying to get my MuP21
to work, I hope I haven't been overlooking an obvious problem:  my DIP
chip (and I assume all of the other DIP chips that were fabricated) has
"MUP21" and "Offete Enterprises" printed upside down on the chip.  The
left-hand notch and the dot over pin 1 both indicate the orientation of
the chip, and I've always assumed that the chip was just printed upside
down.  However, I recently was using a chip (LM1889, a video modulator
chip) that had both the notch and dot on it, and the label was printed
upside down, but upon testing I discovered that the label was actually
right-side up, and the notch and dot were in the wrong place!  This
leads me to suspect that I've actually had my MuP21 wired up backwards
whenever I've tried to use it.
Can anyone please verify that the notch and dot are correct, and the
label is indeed upside down?  Otherwise, I could really kick myself.

--Andrew