Demo for DSP3210 chips

   Author:       wrangler491_at_gmail_dot_com
   Uploader:     Wrangler491 gmail com
   Type:         demo/aga
   Version:      1.04
   Architecture: m68k-amigaos >= 3.0
   Distribution: Aminet
   Kurz:         demo fuer DSP3210-Chips
   Date:         2023-07-04
   Readme:       http://aminet.net/demo/aga/WhatMightHaveBeen.readme
   Downloads:    6

http://aminet.net/demo/aga/WhatMightHaveBeen.lha

This is a demo for the AA3000 and AA3000+ Amigas equipped with fully working

DSP3210 chips (see notes below). This is the extended version produced for

Kickstart 01 in Nottingham in July 2023.

Uses C2P code courtesy of Kalms

Usage:

------

De-archive to a suitable location and from the Shell:

WMHB.exe

You do not need any other files for the demo to run.

Note that if you also have ptreplay.library (from Aminet) and a mod file named

music.mod in the same drawer as the executable then the mod will play during

the demo. Otherwise, silence and a few extra FPS!

In my video on YouTube of the original version of the demo, I was using the

mode "After the Fight" by Boray, available on Aminet.

Notes on getting the demo to run:

---------------------------------

This demo will stress your DSP much more than any other code for the DSP that

is available right now, specifically the DSP <-> FastRAM interface.

In order to get it to work properly, your DSP support logic must be set up

right and you may also need to remove or adjust your accelerator if you are

using one. If you don't do this, the demo may only run for a few seconds, or

not at all and you will get gurus or just your music mod playing.

Start by trying the demo on the onboard 68030 and check that works first

before seeing if it works with your accelerator too. The demo was designed

for an unexpanded AA3000+.

Support logic:

The choice of the four DSP logic chips (U122-124 and U701) is a dark art. At

the time of writing it's not clear there is a perfect combination that works

for everyone. Certainly, using faster chips doesn't guarantee better results.

I am using the following chips and the demo runs faultlessly even with an 060

accelerator running at 100 MHz:

U122 and U124 are ATF22V10C-5JX

U123 is ATF22V10C10JU-PH

U701 is ATF16V8B15JU-PH

The firmware for these chips is on my git here:

https://github.com/Wrangler491/AA3000-DSP

These are modified versions of the firmware in the Haynie archive. (The

firmware for U123 is used from that archive without any changes.)

If that doesn't work, then you could try forcing the demo to run from either

the onboard FastRAM or even ChipRAM by using changemempri, which is available

from Aminet, although you will take a performance hit.

If you can't get the demo to run on the onboard 68030 with these chips and

firmware then you are going to have to experiment with different logic chips.

It is NOT the fault of the demo code.

Accelerators:

Once you add an accelerator to the mix, things get even harder. The demo

works well with accelerators and will show a step up in FPS from using a

68060 at 50 MHz. At 100 MHz the demo will be even faster but not twice as

fast because it becomes limited by the speed for the DSP.

In testing with a BFG9060 card, it became clear that in some set ups, cooling

of the BFG's own logic and RAM was a big factor on stability. This may or

may not apply to other accelerators too. So adding heatsinks and fans to the

accelerator's own chips may help.

Wrangler July 2023

Contents of demo/aga/WhatMightHaveBeen.lha

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                 1660    3378  49.1% -lh5- a002 Jul  4 17:32 WhatMightHaveBeen.readme
[unknown]               120581  360404  33.5% -lh5- 66c2 Jun 19 21:15 WMHB.exe
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         2 files  122241  363782  33.6%            Jul  5 00:16