It's beeen a long time, but I seem to remember that the command LDIR was
really easy to use and very fast!??
love
Freya
- Original Message -
From: Laurens Holst [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Thursday, November 15, 2001 2:01 AM
Subject: Re: Large loops (was: Z80 loops
Freya wrote:
It's beeen a long time, but I seem to remember that the command LDIR was
really easy to use and very fast!??
LDIR is great for moving memory, but the loops described by Laurens are
general purpose.
Greetz,
Patriek
--
For info, see
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld bc,4096-1
ld (hl),0
ldir
Yes, it is the faster method to fill a memory area.
It's surely the smallest way to fill a memory area,
but I believe there is a faster method:
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld (hl),0
rept 4095
ldi
endm
In general, for a loop with more than 256 steps, I use the following
code:
ld bc,ITERATIONS
LOOP: push bc
...
(whatever must be done ITERATIONS times)
...
pop bc
dec bc
ld a,b
or c
jr nz,LOOP
Faster is:
ld b,ITERATIONS mod 256
ld c,(ITERATIONS-1) / 256 +1
LOOP:
{do whatever you
: Monday 22 October 2001 4:44pm
To: [EMAIL PROTECTED]
Subject: RE: Z80 loops
Tony Bedford wrote:
I'm hoping to put together a tip sheet with example
code for newbie Z80 programmers like myself. I'd like
to include your ideas, do you mind?
Sure, they're not MY ideas. Although I did think
TI calc is indeed interesting!
But better wait before going there, the archives are temporarily taken
offline.
--
For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
Title: RE: Z80 loops
Since year and day I have these archives stored on my PC :)
Also, the Z80 documentation of CA3 is based on these docs... Online docs available at http://TeddyWareZ.cjb.net/CA3 (documentation link)
This page still has to be fixed, it has spaces in the image files
are on a company M$ exchange server that modifies you
message (yek).
Greetz
Patrick
- Original Message -
From: Seidel, J
To: '[EMAIL PROTECTED]'
Sent: Tuesday, October 23, 2001 1:49 PM
Subject: RE: Z80 loops
Since year and day I have these archives stored on my PC :)
Also, the Z80
Title: RE: Z80 loops
Guess what?
It **IS** set to plain text!! That's the first thing I tried :)
Even now it's set to plain text (while typing, the layout - Plain text is checked). However, AFTER I hit ctrl+enter or click send, it STILL is sent in HTML format and I *REALLY
It _was_ sent in plain text. I received it as plain text. Maybe Outlook
converts plain text into html whenever it /receives/ the bloody mail?
Keep on posting in plain text, as I use 'mutt'.
Thom 'don't be sorry about the non-html' Z.
On 23.10.2001 at 14:35 Seidel, J wrote:
Guess what?
It
Hi,
This page still has to be fixed, it has spaces in the image files, and
I got a mail from someone who showed me that OR netscape OR linux
can't handle spaces in images on the internet... Anyway, the z80 docs
I was the one who sent you that email. Both Netscape AND Linux (or any
other Unix
The following was recieved by me (Eudora Pro) with
Content-Type: multipart/alternative;
boundary=_=_NextPart_001_01C15BB8.C50D2E50
while normal mails are sent with
Content-Type: text/plain; charset=us-ascii
So definately something is wrong.
Patriek
At 13:49 23-10-01
'Patriek Lesparre' wrote about 'HTML mails (was RE: Z80 loops)' - Tue, Oct 23, 2001 at
05:04:56PM CEST
The following was recieved by me (Eudora Pro) with
Content-Type: multipart/alternative;
boundary=_=_NextPart_001_01C15BB8.C50D2E50
while normal mails are sent with
Content-Type
]]On Behalf Of Patriek
Lesparre
Sent: Saturday 20 October 2001 4:29am
To: [EMAIL PROTECTED]
Subject: Re: Z80 loops
Tony Bedford wrote:
I have a loop that needs to clear a 4096 byte area.
I would like it to be as fast as possible, but this is
not critical.
Even if you do not use a LDIR
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld bc,4096-1
ld (hl),0
ldir
Yes, it is the faster method to fill a memory area.
In general, for a loop with more than 256 steps, I use the following
code:
ld bc,ITERATIONS
LOOP: push bc
...
(whatever must be done ITERATIONS times)
...
pop bc
dec bc
ld a,b
Tony Bedford wrote:
I'm hoping to put together a tip sheet with example
code for newbie Z80 programmers like myself. I'd like
to include your ideas, do you mind?
Sure, they're not MY ideas. Although I did think of the 32bit shift myself,
I probably didn't invent it first. Any experienced Z80
Nestor wrote:
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld bc,4096-1
ld (hl),0
ldir
Yes, it is the faster method to fill a memory area.
It's surely the smallest way to fill a memory area,
but I believe there is a faster method:
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld (hl),0
rept 4095
ldi
endm
I did use this loop expansion inside the core of
Fudebrowser for DOS, but I believe Adriano wrote it out
when porting to UZIX, due to lack of space. This trick
is also used inside
Hi,
I have a loop that needs to clear a 4096 byte area.
I would like it to be as fast as possible, but this is
not critical.
Here's what I came up with:
; need to clear data area
; data area is 4096 bytes
; 4096 = (255*16)+16
ld hl,DATA_AREA
ld c,16
Sent: Friday 19 October 2001 6:42pm
To: [EMAIL PROTECTED]
Subject: Re: Z80 loops
Hi,
What about this?
ld hl,DATA_AREA
ld (hl),0
ld de,DATA_AREA+1
ld bc,4095
ldir
Regards,
Tony Bedford wrote:
Hi,
I have a loop
Tony,
I have a loop that needs to clear a 4096 byte area.
I would like it to be as fast as possible, but this is
not critical.
ld hl,DATA_AREA
ld de,DATA_AREA+1
ld bc,4096-1
ld (hl),0
ldir
:)
=
Adriano Camargo Rodrigues da Cunha ([EMAIL PROTECTED])
Tony Bedford wrote:
I have a loop that needs to clear a 4096 byte area.
I would like it to be as fast as possible, but this is
not critical.
Even if you do not use a LDIR like suggested already, your routine is
pretty inefficient. I'll give you a faster version, so you can learn a few
simple
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