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Old 10 September 2018, 19:49   #34
wairnair
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Join Date: Jul 2017
Location: Budapest
Posts: 270
Tried it under WinUAE, no dice. It had distorted sound, some graphical artifacts and eventually crashed (after 4-5 minutes) and gave a guru.
Here's my thinking..
030 is not a lot more/different than the 020, except quote http://www.cpu-world.com/CPUs/68030/index.html :
- The CPU has additional 256-byte data cache with one clock access time.
- Access time for the instruction cache was reduced by 50% - from two to one clock cycle.
- New burst memory interface can be used to quickly fill-in data and instruction caches.
- On-chip MMU can perform address translation in parallel to other CPU functions.

Since T0 can be run on a 68EC030 (A4000), it doesn't use the MMU. Looks like it's either the absence of data cache or burst memory interface, or both. Otherwise they're just identical..
Now, I went further and looked into the instruction sets. The 030 has LESS instructions than the 020, apart from 5 that are MMU related, only available on the full 030.
So that rules out the instruction set, too. Also, they both have the exact same data addressing modes (based on this https://www.nxp.com/files-static/arc.../M68000PRM.pdf)

So I think it boils down to some timing issue where the 020 just can't provide data in time..

Quote:
Originally Posted by earok View Post
Maybe! I have no idea heh.

I've attached an experimental patch (to tzero_custom) that tries something different - essentially disables the "shake" effect when you get hit etc which MAYBE could have been messing things up. I've only tested it minimally though.

Zip also includes the original copper list file (the one included in my previous attempt was hacked to have lower screen height) if you needed it - just copy to the data folder.

I'm not sure if that'll make things better or not, but may be worth a try to narrow things down a bit.

Last edited by wairnair; 10 September 2018 at 20:26.
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