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From: us048503@mmm.serc.3m.com (Art H. Hurst)
Newsgroups: comp.lang.forth
Subject: HP 48SX uses Forth?
Keywords: Forth
Message-ID: <1991Jun10.142047.20295@mmm.serc.3m.com>
Date: 10 Jun 91 14:20:47 GMT
Article-I.D.: mmm.1991Jun10.142047.20295
Reply-To: ahhurst.3m.com (Art H. Hurst)
Organization: 3M - St. Paul, MN  55144-1000 US
Lines: 42

The latest HP Journal (June 1991) sports a front page picture of the new
HP 48SX showing a routine written in what looks very much like Forth.
The text says " The fundamental basis of the HP 48SX system is the RPL
operating system, which occupies about 18K bytes of the system ROM. This
system first appeared in the HP 18C Business Consultant calculator in
1986. In brief, the system combines elements of Forth and Lisp
providing a multi-object RPN stack and direct and indirect threaded
execution, with both atomic and composite objects, temporary (lambda)
variables, and the ability to pass unevaluated procedures as arguments.
The objects are similar to Forth words, containing the address of the
executable code that defines the object and the data that makes up the
body of the object.

"In this issue" describes what we see on the front page as an example of
EquationWriter which is not discussed in any detail in the issue. The
following is what is shown:

@Program to compute a list of prime numbers
<< 7 -> x
   << { 2 3 5 }
      1 SF
      DO
	2 SF
	3
	DO
	GETI x OVER /
	UNTIL
	   IF SWAP OVER >
	     DUP
        THEN SWAP DROP
	ELSE
	  SWAP
	  IF FP NOT
	  THEN 2 CF NOT


That is the end of the screen on the illustration. Does anyone have any
info on this? Seems as though Forth is still alive deep within HP.


Art Hurst
ahhurst@3m.com