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Altirra w/VBXE emulation


phaeron

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Mr Proper looks like an Amiga game...

 

Not that surprising, when you consider that VBXE has twice the memory bandwidth of an Amiga 500.

 

exe file exchanged but Altirra still does not scroll.

 

Altirra 1.5 test-11 does not support vertical scrolling. You need this version:

 

http://www.virtualdub.org/beta/Altirra-1.5-test12.zip

http://www.virtualdub.org/beta/Altirra-1.5-test12-src.zip

 

Tested with both overlay (80text) and attribute map scrolling. Also fixed a bunch of debugger annoyances.

 

anyway...here is the example with 4x4 cells...

Altirra will let you create an attribute map with fields narrower than 8 pixels, but that is invalid on the real hardware according to the docs.

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as in this version I am writing into XDL+10 at $4000 bank 0 which contains the hscroll offset. (not +11)

 

exe file exchanged but Altirra still does not scroll.

 

I pulled this down, and it looks like the offset should be +11 -- $400A is the high byte of the attribute map stride.

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The valid PERCOM block for such an image should be $01 $00 $fe $ff $00 $04 $01 $00 $FF $00 $00 $00 (1 track * 65534 sectors * 256 bytes = ~16 MB).

 

Sorry, correcting myself: the 16-bit number specifying the number of sectors per track should be in big endian order; so $01 $00 $FF $FE $00 $04 $01 $00 $FF $00 $00 $00 is the correct PERCOM block for a 65534-sector image. I just tried your newest build and saw that it works "almost" well with my ATR images. 32 MB images are accessed without problems:

 

altirra-big.png

 

Now as I have access to the usual Atari software (which I keep on these images) I'll be able to investigate what's the exact problem with the 16 MB DD image (which still generates error 139 on access). Will keep you informed. Thanks.

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But why would you want an 8x8 to cover a 16x8 char?

 

Scrolling isn't much worry - unlike normal DList stuff, you can chunky scroll overlay and attributes much easier thanks to the "Step" parameter. So then all you'd need to do is change the attribute origin parameter, rather than altering multiple LMS parms.

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any idea regarding the instances?

 

I'd have to do some work to implement this, as it requires IPC between the processes and that's annoying to set up. What I usually do is just boot the image again (Alt+B) on the same instance. I'm thinking about having it watch the file and auto-restart, though....

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Here's a little app I wrote to abuse the blitter -- appreciate it if someone could check if this works on a real VBXE. It rotates an image back and forth using the three-shear method.

 

Unfortunately I found out I couldn't do 360 rotation easily since the blitter doesn't have enough address step bits to rotate a 256x256 image, and I need lo/hi XY addressing in order to patch the shear blit lists using the blitter. It also didn't run as fast as I'd hoped, 25 fps in Altirra and probably 16fps on real hardware.

post-16457-126187894759_thumb.png

rotate.zip

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The .OBX file needed the first 2 bytes stripped to work properly.

 

Won't load from DOS... probably since the initial segment goes to $1000.

 

But, works fine from my games loader - but you have garbage appearing outside the pic... VBXE RAM is never cleared on powerup, so probably an idea to initialize it first.

 

 

How many FPS? Hard to tell. It feels like it's slowing down at the end of each "swing". I'd guess probably somewhere between 16-25.

Edited by Rybags
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rotate almost works, hard to say how many fps, i assume still 25 (could you put a color bar for the main loop?)

 

and heaven's scroller works

 

 

edit

 

blitter indicator shows that blitter has some spare time, so the only limit for now is cpu preparing blitter list

post-6723-12618811881_thumb.jpg

Edited by candle
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VBXE Blit Rotate small.zip

 

There's a video - had to crop and reduce the size to keep it within size limits. Divx or XVid codec needed to play it back.

 

Cool, thanks for checking. That looks like it's running about the same speed. Yeah, the garbage is just because I removed the clears to speed it up, and it slows down at the ends because I used a sin table to drive the rotation... and it loads at $1000 because I was too lazy to relocate data manually into VBXE space.

 

I rearranged the blits so that the CPU wasn't the bottleneck, and the emulator still shows the program about 60 scan lines short, so going from 25->50 fps would require something like removing one of the copies, which means adding another fixup blit to switch the framebuffer pointers on shear 3's blits... bleah. Don't feel like doing that at the moment.

 

Still, I'm happy that it worked without me ever touching real hardware. :D

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what's the exact problem with the 16 MB DD image (which still generates error 139 on access).

 

After recalculating all the numbers I found out that the image is broken after all. When I fixed it, it started to work. So this part of Altirra needs no fixes (except the faulty PERCOM block definition as above).

 

Having the basic system working I tried to run the "S2:" driver http://drac030.krap.pl/en-vbxe-pliki.php so that I could use 80-column console under SDX. But the driver does not work, it loads, installs itself in the OS, and then crashes because of illegal instruction at bogus (it seems) PC value. I haven't yet found out, what's the exact cause of the crash.

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That seems to work. Such a PITA that they never bothered to include proper support in Winzip.

Fair enough that you can do it through plugins, but I'd have thought that the rights to such ancient archivers would be next to worthless by now.

 

In fact, you don't need winzip. It's a command line program. And apparently ARC is now under GPL. That would prevent WinZip from including it. I hope 7zip will support it one day though.

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what's the exact problem with the 16 MB DD image (which still generates error 139 on access).

 

After recalculating all the numbers I found out that the image is broken after all. When I fixed it, it started to work. So this part of Altirra needs no fixes (except the faulty PERCOM block definition as above).

 

Whoops, swapped lo/hi bytes... this version should have the PERCOM block fixed:

http://www.virtualdub.org/beta/Altirra-1.5-test13.zip

http://www.virtualdub.org/beta/Altirra-1.5-test13-src.zip

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