[A83] Re: LD A,R ; LD R,A

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: LD A,R ; LD R,A
From: "Kirk Meyer" <kirk.meyer@colorado.edu>
Date: Sat, 14 Jul 2001 08:08:22 -0600
Importance: Normal
In-Reply-To: <200107140640.f6E6eji01847@sunsparc.hysoft-automation.com>
Reply-To: assembly-83@lists.ticalc.org


R is the memory refresh register. I have been told that if you want your RAM
to eventually fade out, do something like this in a loop:

	xor	a
	ld	r,a

Various instructions increment this register by different amounts. It is
usually used in pseudo-random number generators where at most 2 random
numbers per keypress or needed (in this case it is quite random, as it is
based on the user's own timing).

-----Original Message-----
From: assembly-83-bounce@lists.ticalc.org
[mailto:assembly-83-bounce@lists.ticalc.org]On Behalf Of Peter-Martijn
Kuipers
Sent: Saturday, July 14, 2001 12:41 AM
To: assembly-83@lists.ticalc.org
Subject: [A83] LD A,R ; LD R,A



When using the tasm80.tab file, I
came upon the opcodes LD A,R and LD R,A
They have a '1' at the end of the line
(the class), so I guess they're four our
processor. But I'm curious as to that this
R means. It can't be meaning 'other registers'
since they're all taken care for elsewhere in the
table file. My guess is that it's a special system
register like 'I'...

--(Peter-Martijn)

References:

[A83] LD A,R ; LD R,A

From: Peter-Martijn Kuipers <hyper@hysoft-automation.com>