Re: A83: _convop1 prime

To: assembly-83@lists.ticalc.org
Subject: Re: A83: _convop1 prime
From: Jkhum98@aol.com
Date: Fri, 13 Aug 1999 20:17:32 EDT
Reply-To: assembly-83@lists.ticalc.org

In a message dated 8/13/99 6:14:40 PM Central Daylight Time, Jkhum98 writes:

> In a message dated 8/13/99 4:45:58 PM Central Daylight Time, Ted21@aol.com 
> writes:
>  
>  > Does anyone know a romcall that will do the exact opposite of the 
romcall 
>  >  _convop1 (moves op1 into register de).  I want to move a register into 
> op1.  
>  > 
>  >  Any help will be appreciated.
>  >  
>  >  Ted
>  >  
>  
>  There's _setxxop1 and _setxxxxop2, but im sure youre familiar with those 
> already.  For a way to put DE into OP1, try this...
>  
>  push de
>  call _zeroop1
>  pop de
>  ld (OP1+0), e
>  ld (OP1+1), d
>  
>  although the problem there is that I am not sure of the order D and E 
should 
> be loaded into OP1, perhaps someone else knows that. Another problem is it 
> could destroy many other registers, im not sure of which either, but maybe 
> this process can help you. cya...
>  
>  Jason_K
>  TCPA Member
>  tcpa.calc.org
>  

Hmm, I'm sorry, I realized the information I gave was false, once Scott Dial 
reminded me of the FP Number Format that goes into the OP registers. 
Unfortunately, the method I gave is not that easy, you cannot simply load the 
memory locations the OP registers point to, with the values you want the 
whole OP reg to contain.  I cannot think of a better method, so its best if 
you just use the provided romcalls "_setxxop1" and "_setxxxxop2". Those only 
work with A and HL respectively, so to get DE into OP1, you must go through a 
longer process...

push de
call _zeroop1
call _op1toop2
pop hl
call _setxxxxop2
call _op2toop1

Hmm, I hope that helps you. Maybe you already knew that path and were looking 
for a simpler way, but I cant recall any other way to do it. cya...

Jason_K
TCPA Member
tcpa.calc.org