Steem SSE 3.9.2 and Giana Sisters - STE 2014 version

[Acepower]

Hello there and thanks for the greatest Atari ST emulator!

Found a bug that occurs only in Steam SSE 3.9.2 and 3.9.1 as well, with The Great Giana Sisters - STE 2014 conversion by ZAMUEL_A, that is floating around...

There is a sprite color distortion that takes place immediately after a few steps in the game, in any graphics mode, windowed, full screen, Direct3D, non Direct3D, whatever... This bug doesn't occur in Steem SSE 3.9.0 though.

Run the game in both cases, via GIAACSI.TOS, installed in a Megafile 60 HDD, downloaded from Steem SSE Home Page.

Any ideas?

[Steven Seagal]

Hello and thx for the report.
I should have seen it, alas I checked too quickly again.
Unfortunately, it's not so easy to fix, it has to do with blitter timings and bus arbitration, introduced in v3.9.1.
I thought there was a "latching delay" before the blitter started bus arbitration but that seems to be wrong. [EDIT: please see my 2nd post]

in any graphics mode, windowed, full screen, Direct3D, non Direct3D, whatever...

This kind of bug is an emulation issue, it will not be better with some video option (or I would be very surprised! )

[Acepower]

^Thanks, Atari God, looking forward to it!

[Steven Seagal]

In fact, this embarrassing mention only means that I post a lot.
Also forgot to check one of Cyprian's test programs again, BLT_STE, broken too.
But the concept is not compromised contrary to what I thought at first glance. It would have been a real pain.

This is the trouble code in Giana:

Code: Select all

   ori.b #$80,(a4)                                  ; 17AD00: 0014 0080
   bset d0,(a4)                                     ; 17AD04: 01D4
   bne.s -4 {$17AD04}                               ; 17AD06: 66FC


ORI starts the blitter.
It really starts during BSET, right before it reads blitter register, so it reads busy.
In Steem 3.9.1 and 3.9.2, due to missing macros, it starts after that read... that means that it wouldn't restart because BNE sees a zero.

EDIT This problem is fixed here:
https://sourceforge.net/projects/steemsse/files/DevBuilds/

[Acepower]

Wow! That was fast! Just tried it, works great... Thank you Steven Seagal, see you at 393!

[Steven Seagal]

Yes, this one problem is fixed, but it hasn't been tested a lot yet on other programs...
Maybe the next game you try, it displays wrong