A Teletype Model 43 could be considered "portable", and to my
recollection it used a 7x9 dot matrix printhead, which did lower case
nicely. It also used "real" paper as opposed to the thermal stuff of
the TI Silent 700's. It was definitely noisier than a Silent 700, but
the 43 was very nice to use.
I used one of these for a time a long time ago, and found it to be a
really nice terminal for use on timesharing systems. Would love to find
one today.
I have a couple of TI Silent 700's in that have built-in acoustic
couplers, and do lower case...except that the lower case is just a
shrunken down version of the upper case character set. Readable, but
definitely what you'd want to print out RUNOFF documents with. Plus,
that thermal paper isn't very durable for long-term document storage.
Rick Bensene
The Old Calculator Web Museum
http://oldcalculatormuseum.com