|Re: Why is the 28S so cheap?|
Message #9 Posted by James M. Prange (Michigan) on 17 May 2006, 6:03 p.m.,
in response to message #1 by Egan Ford
I am considering a 28S as my travel calculator. I like the 4 line
display and am not religious about RPN vs. RPL. I also like that
it is self-contained, i.e. the calculator is the case.
Well, genuine leather cases are available, although closing a
clamshell model does offer a lot of protection to the keyboard and
I see only positives, so why are they so cheap?
Well, it helps when something isn't categorized well, like
But seriously, "Classic RPN" aficionados usually aren't interested
because the 28 series are RPL, and most RPL users prefer the 48 or
Is there a problem with the hinge?
I've often thought and read that the flex circuit for the hinge
could break, but I don't believe that I've ever read of that
The hinged design can seem a bit clumsy, but as Bruno noted, it
makes it a lot easier to type in commands without hitting the
ALPHA key all of the time. By the way, even with the 48 and 49
series, I often find it easier to simply type in the command
rather than using the menus.
Battery life or performance?
I suppose that a "typical" battery life would be maybe six months.
To me, the performance is adequate for most tasks.
The batteries are a nuisance to change, and apparently since most
users won't want to risk a "memory lost", they're often in a rush
to get the fresh cells in, hence the frequent reports of broken
battery covers, or even the case at the battery cover. The "N"
cells are also somewhat unusual, so a "fresh" cell may have been
"on the shelf" for a very long time. The "N" cells tend to be a
bit expensive too.
Does the 28S support bidirectional transfer? It is important that
it does not.
No, the 28 series IR is unidirectional, only for output to a
printer, and the encoding of the bytes is unusual. See the
82240B Infrared Printer Technical Interfacing Guide if
you're interested in the details of the IR output.
"Wired" I/O isn't built-in. There have been "hardware hacks" to
add bi-directional I/O (RS-232 compatible, IIRC) to the 28 series,
but once the 48SX became available, there wasn't all that much
interest in "fixing" the 28 series.
The biggest problem that I have with the 28 series is that the
only way to restore a "saved" (to a print-out) object is by keying
it in all over again.
The 28 series lacks some commands available in the 48 and 49
series, and they aren't expandable as the 48SX, 48GX, and 49g+
are. Note that RPL objects take more memory than the (more or
less) equivalent objects in "Classic RPN" calculators, so even
"32KB" can be a bit limiting.