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Search: Posts Made By: FSizzle
Forum: Coders. Asm / Hardware 17 February 2020, 19:17
Replies: 16
Views: 601
Posted By FSizzle
On 68020 the prefetch is on longword boundaries...

On 68020 the prefetch is on longword boundaries though.
Forum: Coders. Asm / Hardware 17 February 2020, 18:08
Replies: 16
Views: 601
Posted By FSizzle
Regarding: "cnop 0,2" before functions ...

Regarding: "cnop 0,2" before functions



I guess it's redundant and could simply be omitted if the assembler is known to enforce minimum 2 byte alignment for instructions anyway.

I was...
Forum: Coders. Asm / Hardware 17 February 2020, 04:35
Replies: 16
Views: 601
Posted By FSizzle
Are you talking about code you write yourself, or...

Are you talking about code you write yourself, or code generated by the compiler (such as vbcc)?

If you are writing asm yourself, you can probably chose per-function what your alignment should be....
Forum: Coders. Asm / Hardware 31 January 2020, 08:48
Replies: 30
Views: 1,504
Posted By FSizzle
Thanks Toni. That behavior is a little...

Thanks Toni.


That behavior is a little surprising. I wonder why it is this way. No doubt there is some hardware reason.
Forum: Coders. Asm / Hardware 30 January 2020, 17:47
Replies: 30
Views: 1,504
Posted By FSizzle
This post asks: Can you clear memory using...

This post asks:

Can you clear memory using disk DMA?

Which is a fascinating question to me because it's not one I heard before.

Assuming it's possible, the implicit follow up question is:
...
Forum: Coders. Asm / Hardware 30 January 2020, 07:44
Replies: 30
Views: 1,504
Posted By FSizzle
That function uses the blitter. OP is asking...

That function uses the blitter. OP is asking about using disk DMA.
Forum: Coders. Asm / Hardware 30 January 2020, 05:41
Replies: 30
Views: 1,504
Posted By FSizzle
When clearing, using one channel only, the...

When clearing, using one channel only, the blitter cannot write during every available DMA slot. In the same way that you can clear memory on the 68000 more quickly by using the blitter and CPU...
Forum: Coders. Asm / Hardware 16 January 2020, 17:50
Replies: 18
Views: 619
Posted By FSizzle
The HRM is confusing in places, and this is...

The HRM is confusing in places, and this is certainly one of them. As Toni says, the "joining tones" section is probably the best description of the behavior for "automatic" mode (DMA based sample...
Forum: Coders. Asm / Hardware 16 January 2020, 05:25
Replies: 18
Views: 619
Posted By FSizzle
The Audio interrupt triggers not at the end of...

The Audio interrupt triggers not at the end of playback, but rather shortly after the start when the audio registers have been internally copied. This allows you to queue the "next" waveform shortly...
Forum: Coders. Asm / Hardware 11 April 2019, 06:05
Replies: 27
Views: 1,969
Posted By FSizzle
It is quite common for packers which can...

It is quite common for packers which can decompress in-place to require the source to be aligned to the end of the buffer rather than the start.

i.e. if input size = $400 and output size = $1000...
Forum: Coders. Asm / Hardware 30 March 2019, 03:21
Replies: 66
Views: 3,347
Posted By FSizzle
I'm don't understand what you mean. Do you mean...

I'm don't understand what you mean. Do you mean there is some way to do this on current hardware? Or do you mean on some hypothetical hardware it would be possible?


Can you explain a bit more...
Forum: Coders. Asm / Hardware 28 March 2019, 03:52
Replies: 66
Views: 3,347
Posted By FSizzle
A single 6 plane interleaved blit with mask or 6...

A single 6 plane interleaved blit with mask or 6 individual blits with mask takes the same amount of blitter DMA cycles. The interleaved blit requires that you duplicate all the lines in your mask so...
Forum: Coders. Asm / Hardware 17 November 2018, 20:45
Replies: 89
Views: 7,806
Posted By FSizzle
Interesting. I see there was some investigation...

Interesting. I see there was some investigation in the other thread, but it looks like that was more for the other glitch being reported.

Is there anything I can do to help narrow down this...
Forum: Coders. Asm / Hardware 22 September 2018, 03:43
Replies: 13
Views: 1,149
Posted By FSizzle
Take care to either write both the high and low...

Take care to either write both the high and low address for the jmp destination, OR make sure the jmp destination is in the same 64KiB aligned block as the copper list start address if you only set...
Forum: Coders. Asm / Hardware 22 July 2018, 08:45
Replies: 89
Views: 7,806
Posted By FSizzle
you need default color table to be compatible...

you need default color table to be compatible with OCS/ECS
This only seems to relate to dual playfield setup, but I think it makes sense to drive these to defaults, so I've done that.


In my...
Forum: Coders. Asm / Hardware 21 July 2018, 20:01
Replies: 89
Views: 7,806
Posted By FSizzle
So finally, thanks to all the help in this thread...

So finally, thanks to all the help in this thread (which is really appreciated - thank you Toni and ross!), I have everything lining up nicely on AGA.

For anyone following the thread who might...
Forum: Coders. Asm / Hardware 21 July 2018, 04:49
Replies: 89
Views: 7,806
Posted By FSizzle
Upon closer analysis, it looks like the BRDRBLNK...

Upon closer analysis, it looks like the BRDRBLNK also ends 70ns early. i.e. the BRDRBLNK starts and stops 70ns early.

58954
Forum: Coders. Asm / Hardware 21 July 2018, 04:03
Replies: 89
Views: 7,806
Posted By FSizzle
The early BRDRBLNK is a hires pixel (70ns) before...

The early BRDRBLNK is a hires pixel (70ns) before bitplane data (3rd row), same width as the color delay shown on row 2.

58953
Forum: Coders. Asm / Hardware 21 July 2018, 03:50
Replies: 89
Views: 7,806
Posted By FSizzle
@Toni. For completeness, all the tests I have...

@Toni. For completeness, all the tests I have done on my real A1200 have been via an Indivision Mk2. I actually thought for a while that this might somehow be responsible for some of these issues, so...
Forum: Coders. Asm / Hardware 20 July 2018, 02:14
Replies: 89
Views: 7,806
Posted By FSizzle
Thanks Toni! - I confirm that with this version,...

Thanks Toni! - I confirm that with this version, the delay in WinUAE matches my real A1200. You are a machine! :)

I'd love hear your thoughts on the "early BRDRBLNK" issue if you have chance to...
Forum: Coders. Asm / Hardware 20 July 2018, 02:05
Replies: 89
Views: 7,806
Posted By FSizzle
@ross +1 I would also find this very interesting.

@ross +1 I would also find this very interesting.
Forum: Coders. Asm / Hardware 20 July 2018, 01:59
Replies: 89
Views: 7,806
Posted By FSizzle
I have discovered another interesting thing...

I have discovered another interesting thing related to all this. On AGA the BRDRBLNK is applied a half pixel early on the left hand side on real hardware! Interestingly it is applied at the expected...
Forum: Coders. Asm / Hardware 19 July 2018, 04:54
Replies: 89
Views: 7,806
Posted By FSizzle
My target is OCS, so I will continue to sync...

My target is OCS, so I will continue to sync there. I just want to do some extra stuff on AGA to make it look correct (not have the misalignment)

My plan is to check if running on AGA and build...
Forum: Coders. Asm / Hardware 18 July 2018, 08:33
Replies: 89
Views: 7,806
Posted By FSizzle
@Toni - Very nice. :great For what it's worth, I...

@Toni - Very nice. :great For what it's worth, I think going for accuracy is the right approach - I like the idea of all bugs and hardware quirks being emulated correctly (something WinUAE already...
Forum: Coders. Asm / Hardware 15 July 2018, 21:32
Replies: 89
Views: 7,806
Posted By FSizzle
When I boot the halfhres exe there are...

When I boot the halfhres exe there are differences vs WinUAE as follows (for the 5 different states of the test):
- 1 - every second pixel misaligned on left side. Right shows extra non-white pixel...
Forum: Coders. Asm / Hardware 15 July 2018, 01:06
Replies: 89
Views: 7,806
Posted By FSizzle
I've uploaded a new HalfPixelTest.exe. This...

I've uploaded a new HalfPixelTest.exe. This simplifies the repro (exe is now 252 bytes :)) and also eliminates some on-screen garbage when running from the WB or CLI.

@Toni. Let me know if this is...
Forum: Coders. Asm / Hardware 14 July 2018, 22:43
Replies: 89
Views: 7,806
Posted By FSizzle
Uploaded source for HalfPixelTest.exe I uploaded...

Uploaded source for HalfPixelTest.exe I uploaded (it's the same as the bootblock.s, but with 2 changes):
- Set the FMODE to 0 in the copper list
- Remove the DOS header required for boot blocks
Forum: Coders. Asm / Hardware 14 July 2018, 22:39
Replies: 89
Views: 7,806
Posted By FSizzle
Uploaded HalfPixelTest.exe.

Uploaded HalfPixelTest.exe.
Forum: Coders. Asm / Hardware 14 July 2018, 21:44
Replies: 89
Views: 7,806
Posted By FSizzle
I've uploaded a sample that reproduces the issue:...

I've uploaded a sample that reproduces the issue:
- a bootblock.s
- a bootable ADF image with that bootblock

I've also attached some images:
- Screenshot of WinUAE A1200 where everything...
Forum: Coders. Asm / Hardware 14 July 2018, 17:37
Replies: 89
Views: 7,806
Posted By FSizzle
I'll create a stand-alone repro.

I'll create a stand-alone repro.
Forum: Coders. Asm / Hardware 14 July 2018, 08:55
Replies: 89
Views: 7,806
Posted By FSizzle
Half pixel copper delay on A1200 hardware

I have some code that uses the copper to set color00 every line, synchronized with the DIWSTRT/STOP (to get an extra color out of OCS amigas).

It works perfectly in WinUAE with OCS and AGA...
Forum: Coders. Asm / Hardware 11 November 2017, 18:36
Replies: 9
Views: 1,687
Posted By FSizzle
I decided to investigate this a bit, so I created...

I decided to investigate this a bit, so I created a small test (with sprites and bitplanes disabled), which changes the color at the right edge of the screen, setting the wait at each pixel position...
Forum: Coders. Asm / Hardware 10 November 2017, 04:20
Replies: 9
Views: 1,687
Posted By FSizzle
It's possible to have the screen finish 16px...

It's possible to have the screen finish 16px later, thus keeping the full width, all the sprites and scrolling, as far as I can tell, but it introduces some new potential problems.

Firstly, I...
Forum: Coders. Asm / Hardware 02 November 2017, 03:35
Replies: 9
Views: 1,687
Posted By FSizzle
Thanks for the great info everyone. Looks like...

Thanks for the great info everyone. Looks like I'll need to shrink the window by 16 pixels on the left if I want that 7th sprite to work reliably on all hw (on the plus side I'll get the 8th one back...
Forum: Coders. Asm / Hardware 01 November 2017, 08:39
Replies: 9
Views: 1,687
Posted By FSizzle
Thanks for confirming that at least what I'm...

Thanks for confirming that at least what I'm trying to do should work :) I do suspect it's something wrong with my code, but I'm a little stumped as to what it might be.

If I change the DDFSTRT to...
Forum: Coders. Asm / Hardware 01 November 2017, 03:55
Replies: 9
Views: 1,687
Posted By FSizzle
7th sprite corrupt with DDFSTRT of 0x30

I'm having a weird problem with my 7th sprite being corrupt when I start my DDSTRT earlier (0x30 instead of 0x38) in order to have HW scrolling.

I fully expect to lose the 8th sprite, but I'm...
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