🚀 go-pugleaf

Help a poor non-EE :

I am trying to convert a TTL signal into an RS-232 signal.  I was
under the impression that this can be done simply with the MC1488
monolithic quad serial line driver.  Here is my set-up:

                  2 |----------| 3
     TTL ---------->|          |---------> RS-232
                  1 | MC 1488  | 14
     -5 V --------->|          |<--------- +5 V
                  7 |          |
     GND ---------->|----------|

What I get:

When the TTL input is at 0 V, the RS-232 output is at 3.25 V.  When
the TTL input is at +5 V, the RS-232 output is at 3.94 V.  Needless to
say, this is useless.

All the power supply lines have been check and re-checked.

Do I have a bad chip or am I missing some glue?

Any help would be greatly appreciated,

- Kurt
Kurt Geisel                       SNAIL :
Carnegie Mellon University            65 Lambeth Dr.
ARPA : kg19+@andrew.cmu.edu           Pittsburgh, PA 15241
UUCP : uunet!nfsun!kgeisel  "We just need to short-circuit the continuum on a
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