LE> SP-64
 LE> Serial-To-Parallel Converter
 LE> and 64K Buffer
 LE> Product No.
 LE> 8149-1

 LE> It's got a coax power jack, and no indication of what voltage
 LE> polarity it wants. There's also a 8 position DIP switch inside
 LE> (probably for setting serial parameters).

Got any 74xx TTL inside?  The +5/G were typically 14/7 or 16/8.
Stick an ohm meter on it and see which is straight through to the
jack.

... Lord give me patience, but I want it NOW!
___ MultiMail/MS-DOS v0.35

---