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From: bson@rice-chex.ai.mit.edu (Jan Brittenson)
Newsgroups: comp.sys.handhelds
Subject: Re: Questions about hp48 machine language
Keywords: hp48, machine language, ml
Message-ID: <15427@life.ai.mit.edu>
Date: 30 Apr 91 03:57:18 GMT
References: <42247@netnews.upenn.edu>
Sender: news@ai.mit.edu
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In a posting of [29 Apr 91 22:05:09 GMT]
   hoford@sequoia.circ.upenn.edu (John Hoford) writes:

 > Q2
 > I have been using "MLDL 1.01" ... My problem is it does not have a
 > simple way of getting the starting address of a program in a variable.

   Recall the variable and pass the CODE object as an argument on
level 1.

 > So the question: Does anyone have a program That returns the address
 > of the start of a stored program ?'

   In MLDL 1.02 the XLIB 1092 7 takes a code object and returns its
address plus 10 in both level 1 and 2. So, to get the address of a
CODE object in level 1 the following program can be used:

  \<< 1092 # 18CEAh SYSEVAL # 4035h SYSEVAL # 7E50h SYSEVAL 
      EVAL DROP # 59CCh SYSEVAL 10 -
  \>>

   Notice that MLDL 1.02 must be attached, and it will *not* work with
1.01.

 > ie.
 > label ->addr   1: #213FF 
 > Would the address change to quickly to be useful?

   It's a ROM address. It won't change. If it were a RAM address, then
generally, the answer is no. Programs and directories move around much
less than other objects.


 > The STAR assemblers seem to produce raw ml.  Is their a progam which
 > will put them into a "asc->" or a "hp/kermit file" format?

   You can use the HEADER macro defined in hp48.star, it will create a
kermit header. If you want a code object, you can use the
CODE...ENDCODE macro. Just make sure to assemble with hp48.star.
You can use the following skeleton:


	;;+
	;; HP-48 ML Skeleton Program
	;;
	;; Assemble with hp48.star:
	;;
	;;	% star listing binary hp48 skeleton
	;;
	;;-

	; This is the kermit header.

		header

	; This is a CODE...ENDCODE macro invocation.
	; Don't break the code object into several files.

		code

		; the code goes here

		move.a	@d0, a		; Continue RPL thread
		add	5, d0		;	-- "" --
		jump	@a		;	-- "" --

		endcode


;;---
						-- Jan Brittenson
						   bson@ai.mit.edu