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From: ji@close.columbia.edu (John Ioannidis)
Newsgroups: comp.sys.handhelds
Subject: Re: HP48SX
Message-ID: <1990Mar12.140344.10869@cs.columbia.edu>
Date: 12 Mar 90 14:03:44 GMT
References: <1290@mindlink.UUCP>
Sender: news@cs.columbia.edu (The Daily News)
Reply-To: ji@close.UUCP (John Ioannidis)
Organization: Columbia University Department of Computer Science
Lines: 32

In article <1290@mindlink.UUCP> a309@mindlink.UUCP (George Lin) writes:
>1) The serial number on my 48SX is 3003A00256.  Does this mean my calculator is
>the 256th one off the production line?

HP's serial numbers are in the form YYWWCNNNNN, where YY is the number 
of years since 1960, WW is the week of the year, C is the country code
(A=USA, S=Singapore, M=Mexico etc) and NNNNN is the serial number itself. 
Now, I was under the impression that NNNNN was monotonically increasing,
not starting at 0 (or 1) every time YY or WW changed. I'm probably wrong,
since my calculator is 3009A00098. See, it can't be the 98th calculator
off the production line (which is what I thought) and have been produced
in the 9th week of 1990 (1960+30) and yours be the 256th and be produced
the third week of 1990. Unless you reported the WW code wrong!


>
>2) How about an IR I/O interface for the PC so that one does not need to 'plug
>in' their HP to transfer data?
>

I have no idea what IREDs/IRdiodes they are using; use a stronger IRED
in your end and you can fry their photodiode (OK, IRdiode!). I remember
this used to be a problem with the 41 WAND; people had made circuits
driven by their PCs to flash a red LED at their WAND and ended up frying
them (the solution was to put some diffusing material like cotton wool
between them; which is not acceptable in the 48 case). 

I undertand the reluctance to electrically hook up the 48 to a PC,
but the IR link will only run up to 2400 baud, as opposed to 9600 for
the serial link.

/ji