Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!uw-beaver!Teknowledge.COM!unix!hplabs!hp-pcd!hpcvia!rayde
From: rayde@hpcvia.CV.HP.COM (ray_depew)
Newsgroups: comp.sys.handhelds
Subject: Re: HP48SX impressions
Message-ID: <31210004@hpcvia.CV.HP.COM>
Date: 19 Mar 90 17:06:37 GMT
References: <9003110211.AA03686@en.ecn.purdue.edu>
Organization: Hewlett-Packard Co., Corvallis, Oregon
Lines: 35

>  steele@EE.ECN.PURDUE.EDU (Richard A. Steele)
>  Date: Sat, 10 Mar 90 18:11:45 PST

>  I'm extremely dissapointed with the binary number operations.  Still
>  no signed (1's and 2's complement) binary arithmetic, and entering
>  the buggers is a pain (the binary objects are exactly like the

You're in luck!  You can get signed (2's complement) binary numbers, and
they work in add/subtract/multiply.  I think divide works too,
but my limited experience with it hasn't been all that exciting.

To get a negative binary integer, for example, negative #1d, DON'T press

# 1 [+/-] [ENTER]

Instead, press

# 1 [ENTER] [+/-]

and you will see #18446744073709551615d.  The HP-48SX sees #1d internally 
as 63 zeroes and a one.  When you press [+/-], the HP-48SX changes all teh
ones to zeroes and all the zeroes to ones, and adds 1 to the result.  That's
the 2's complement.  So instead of 63 zeroes and a one, you have 64 ones, or
#18...d, or #FFFF FFFF FFFF FFFFh.


>  How about a
>  HELP key that lists the purpose of a key (and its shifted cousins).

The Serial Kit disk contains a program, USAG, which works well as a HELP 
command.  I think USAG can be downloaded from the HP BBS, too.

Ray Depew
HP InkJet Components Operation
"An original idea?  How quaint!"