Just another Blitter demo

All 680x0 related coding posts in this section please.

Moderators: exxos, simonsunnyboy, Mug UK, Zorro 2, Moderator Team

User avatar
Cyprian
Atari God
Atari God
Posts: 1404
Joined: Fri Oct 04, 2002 11:23 am
Location: Warsaw, Poland

Re: Just another Blitter demo

Postby Cyprian » Fri Oct 28, 2016 7:40 pm

Anima wrote:Do you know the cycle numbers for clearing? I thought it was 4 cycles on both Blitters...

Edit: now I know what you mean: because the CPU is clocked at 8 MHz makes the Atari Blitter faster


Faster Atari bus is one factor, the other one is a buggy amiga chipset.
Amiga blitter needs one idle cycle per each copying/clearing word. It means that copy takes 3 bus cycles and clearing takes 2 bus cycles per word.
Therefore, during the border area (when video DMA is off) clearing takes 4 CPU cycles per word and on the visible area 8 CPU cycles per word. It is valid for 4 bitplane mode, and each additional bitplane increases copy/clearing process by further 2 CPU cycles per word.

In case of the Atari, it is always 4 CPU cycle per each word.
Jaugar / TT030 / Mega STe / 800 XL / 1040 STe / Falcon030 / 65 XE / 520 STm / SM124 / SC1435
SDrive / PAK68/3 / CosmosEx / SatanDisk / UltraSatan / USB Floppy Drive Emulator / Eiffel / SIO2PC / Crazy Dots / PAM Net
Hatari / Aranym / Steem / Saint
http://260ste.appspot.com/

tcat
Atari freak
Atari freak
Posts: 73
Joined: Fri May 03, 2013 6:00 am

Re: Just another Blitter demo

Postby tcat » Tue Nov 29, 2016 7:48 pm

Hi,

Very impressive.
Can it be adapted for the ST as well?

Many thanks
Tom

User avatar
Anima
Atari Super Hero
Atari Super Hero
Posts: 655
Joined: Fri Mar 06, 2009 9:43 am
Contact:

Re: Just another Blitter demo

Postby Anima » Fri Dec 02, 2016 7:20 am

tcat wrote:Can it be adapted for the ST as well?

I am afraid that the ST does not benefit from this due to the lack of the Blitter.

tcat
Atari freak
Atari freak
Posts: 73
Joined: Fri May 03, 2013 6:00 am

Re: Just another Blitter demo

Postby tcat » Fri Dec 02, 2016 7:53 am

Hi,

My ST has the Blitter installed along with Rainbow TOS.

Tomas

User avatar
Anima
Atari Super Hero
Atari Super Hero
Posts: 655
Joined: Fri Mar 06, 2009 9:43 am
Contact:

Re: Just another Blitter demo

Postby Anima » Fri Dec 02, 2016 9:51 am

tcat wrote:My ST has the Blitter installed along with Rainbow TOS.

Ah, ok. That's a different story. However, the demo itself uses at least one STE address (Shifter low byte) which prevents it from running on an ST. I'll try to fix this soon that you can try it on your machine as well.

User avatar
Cyprian
Atari God
Atari God
Posts: 1404
Joined: Fri Oct 04, 2002 11:23 am
Location: Warsaw, Poland

Re: Just another Blitter demo

Postby Cyprian » Fri Mar 31, 2017 10:43 pm

Anima wrote:
leonard wrote:Could be interesting to know how many 32*31, 3pl sprites can run on an normal amiga 500.

Maybe Frank B. can give us some numbers? ;)


according to this page A500 can run ~19 bobs 32x24 per frame (draw/restore) on a 320x256x5 screen

and this tool shows 17 bobs 32x32 per frame (save/draw/restore) on a 320x200x4 screen

btw. Anima is it your tool? https://jsfiddle.net/rcvbakLa/
Jaugar / TT030 / Mega STe / 800 XL / 1040 STe / Falcon030 / 65 XE / 520 STm / SM124 / SC1435
SDrive / PAK68/3 / CosmosEx / SatanDisk / UltraSatan / USB Floppy Drive Emulator / Eiffel / SIO2PC / Crazy Dots / PAM Net
Hatari / Aranym / Steem / Saint
http://260ste.appspot.com/

User avatar
Anima
Atari Super Hero
Atari Super Hero
Posts: 655
Joined: Fri Mar 06, 2009 9:43 am
Contact:

Re: Just another Blitter demo

Postby Anima » Thu Apr 06, 2017 3:39 pm

Cyprian wrote:according to this page A500 can run ~19 bobs 32x24 per frame (draw/restore) on a 320x256x5 screen

and this tool shows 17 bobs 32x32 per frame (save/draw/restore) on a 320x200x4 screen

btw. Anima is it your tool? https://jsfiddle.net/rcvbakLa/

Yes, I was curious how the Amiga Blitter performance is affected by all the custom DMA devices. I am not sure if the results are realistic.


Social Media

     

Return to “680x0”

Who is online

Users browsing this forum: No registered users and 3 guests