Baremetal Amiga Emulator - Page 2

Toni Wilen · 05 February 2018, 14:12

If I remember correctly, KS 1.x boot screen assumes blitter undocumented feature: linedraw mode uses C modulo register for both C and D channels. D modulo is ignored. (There are also other linedraw undocumented features but they are not needed to get KS code working)

bloodline · 05 February 2018, 15:10

Quote:

Originally Posted by Toni Wilen

If I remember correctly, KS 1.x boot screen assumes blitter undocumented feature: linedraw mode uses C modulo register for both C and D channels. D modulo is ignored. (There are also other linedraw undocumented features but they are not needed to get KS code working)

Thanks for the steer! I have fiddled around with the code a bit and now get this with line mode enabled.

It's still a million miles from working, but at least it doesn't crash now

bloodline · 05 February 2018, 16:48

I just had my first Guru which displayed the proper screen... sadly a bit messed up, so I can't read the guru number, but I'm still very excited!

nogginthenog · 05 February 2018, 20:08

Nice

Reminds me of the early UAE days when Bernd Schmidt posted similar screenshots (possibly to USENET?).

bloodline · 06 February 2018, 20:51

Quote:

Originally Posted by nogginthenog

Nice

Reminds me of the early UAE days when Bernd Schmidt posted similar screenshots (possibly to USENET?).

I can imagine the excitement that must have generated! I've spent far too long on the blitter, Kickstart 3.0 isn't even close to booting... I've basically run out of time now as I have to go back to work tomorrow. But getting this far has been really good fun... I wonder if my blitter is good enough to make a working floppy emulation?

bloodline · 10 February 2018, 00:00

I have been over my line mode code (disabling the area copy mode) and it's clearly working to some degree...

I never realised that the boot screen was drawn by the blitter

Sinphaltimus · 10 February 2018, 01:28

Sweet. Congrats!

bloodline · 10 February 2018, 11:05

Ok, running the line mode and the area copy modes together yields this.

I'm going to leave the line mode alone for a bit now, since I spent ages trying to get it to work (and it clearly still doesn't work right), almost all the issues I have with it are to do with the Amiga's bit addressing of pixels... so much bit shifting

I suspect there may be problems because I'm not leaving the registers in the correct state when my functions return... Amiga coders seem want to take advantage of observed behaviour, rather than following the tech docs.

Looking back at the screenshots I have posted, is a great way to see how much I have learnt (seriously, this has to be one of the best ways to learn how this stuff works).

-Edit- One idea I have toyed with is using "byteplane" buffer... so the blitter copies in the pixel data, and stores each bit in as a byte in the internal buffer (obviously this requires 8 times as much memory), operates on the byte buffer, then then once the blitter operation is completed copies the data back to the original format...

AMIGASYSTEM · 10 February 2018, 11:54

Quote:

Originally Posted by Sinphaltimus

I wish someone would do this for x86 as a competitor to AROS since AROS is such a pain with hardware that it's hardly worth fishing for appropriate gear anymore. In that regard I have one more desktop PC to try IcAros on in the coming weeks, if that fails, I'll be done trying it for good unless some huge breakthru happens with the drivers..

To use IcarOS to the best you must have a PC with compatible hardware, HERE find the database of all Hardware compatibility, between the one arrives also the new AspireOS (another beautiful distro AROS)

Sorry OT

bloodline beautiful project

bloodline · 10 February 2018, 12:22

Quote:

Originally Posted by AMIGASYSTEM

To use IcarOS to the best you must have a PC with compatible hardware, HERE find the database of all Hardware compatibility, between the one arrives also the new AspireOS (another beautiful distro AROS)

Sorry OT

bloodline beautiful project

No problem about being off topic, I've been involved with AROS since 1999

I think there are still some commits by me in the code base.

On Topic: Can the blitter access address that are not word aligned? The C and D channels seem regularly loaded with odd addresses by the kickstart... Which doesn't seem right to me (I'm currently ignoring the least significant bit).

bloodline · 11 February 2018, 12:02

I appear to have a working line mode implementation now. I'm guessing the missing vertical and horizontal areas are to be filled by the area copy mode.

But my area copy mode is totally broken... I assumed that area mode would be the easy part... time for (another) rewrite.

bloodline · 11 February 2018, 13:59

Area mode rewrite... almost there?!

bloodline · 11 February 2018, 14:17

Something still not right... but this is enough for today

-Edit-
The attached executable, is compiled for MacOS Sierra, and requires libSDL 2.0+ installed.

Run from command line:

zorro <path to rom image>

It will spew out quite a bit of debugging info... enjoy.

wodan · 11 February 2018, 14:31

Could be an off by one error (as in one word to the side), looks like you're close!

bloodline · 11 February 2018, 14:38

Quote:

Originally Posted by wodan

Could be an off by one error (as in one word to the side), looks like you're close!

Yup, I know the problem is with the shifting section, as it gets to this point when disabled and I only get corruption when it's enabled, and it's clear the text is rendered one word off alignment. I'll fix it when I have a free moment tomorrow.

And I guess we can now officially say there are three Amiga emulators, UAE, Fellow and "Zorro" though mine only boots KS1.2 (and also 1.3)... nothing more.

-Edit- it has been such good fun getting to this point, many thanks to all who have followed and made suggestions! I'm definitely going to try and get the floppy working... my guess here is where my total disregard for timings will make the project fall apart.

LaBodilsen · 11 February 2018, 19:48

Quote:

Originally Posted by bloodline

On Topic: Can the blitter access address that are not word aligned? The C and D channels seem regularly loaded with odd addresses by the kickstart... Which doesn't seem right to me (I'm currently ignoring the least significant bit).

You would be right to do that.

From this: http://amigadev.elowar.com/read/ADCD.../node012D.html

Quote:

* Modulos and pointers are in bytes; width is in words and height is in
pixels. The least significant bit of all pointers and modulos is
ignored.

Nice progress, and it's nice with all the updates. keep it up.

malko · 11 February 2018, 22:06

Quote:

Originally Posted by bloodline

[...] And I guess we can now officially say there are three Amiga emulators, UAE, Fellow and "Zorro" though mine only boots KS1.2 (and also 1.3)... nothing more.[...]

Wonderful !

Quote:

Originally Posted by bloodline

[...]-Edit- it has been such good fun getting to this point, many thanks to all who have followed and made suggestions! I'm definitely going to try and get the floppy working... my guess here is where my total disregard for timings will make the project fall apart.

No stress

.

rare_j · 11 February 2018, 22:11

I haven't made suggestions but I have followed. I hope you continue to build on this as long as you're having fun

bloodline · 12 February 2018, 07:30

Quote:

Originally Posted by LaBodilsen

You would be right to do that.

From this: http://amigadev.elowar.com/read/ADCD.../node012D.html

Nice progress, and it's nice with all the updates. keep it up.

I hope people aren't getting a bit fed up with all my failures!

I found the Abacus book "Amiga Intern" (as suggested by user ASM68 in another thread) and this page here http://www.winnicki.net/amiga/memmap/LineMode.html really helpful to debug the blitter.

The thing which really threw me off with the Line Mode, was why all the values were multiplied by 2... but then it dawned on me that the bltxmod and bltxpt registers probabaly don't have the least significant bit connected, so the values are just left shifted to fit! Once I figured that out (took 9 days), the implementation was quite easy.

I was able to fix the shifting section and now we have what appears to be a fully working boot of KS1.2!

bloodline · 12 February 2018, 07:40

Quote:

Originally Posted by rare_j

I haven't made suggestions but I have followed. I hope you continue to build on this as long as you're having fun

This has been a lot of fun (I can't wait to clean up the sources and publish them), I will now see just how far I get with floppy emulation, and then I'll need to add hires mode... this is addictive

05 February 2018, 16:48	#23
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	I just had my first Guru which displayed the proper screen... sadly a bit messed up, so I can't read the guru number, but I'm still very excited! Attached Thumbnails

10 February 2018, 00:00	#26
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	I have been over my line mode code (disabling the area copy mode) and it's clearly working to some degree... I never realised that the boot screen was drawn by the blitter Attached Thumbnails

10 February 2018, 11:05	#28
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	Ok, running the line mode and the area copy modes together yields this. I'm going to leave the line mode alone for a bit now, since I spent ages trying to get it to work (and it clearly still doesn't work right), almost all the issues I have with it are to do with the Amiga's bit addressing of pixels... so much bit shifting I suspect there may be problems because I'm not leaving the registers in the correct state when my functions return... Amiga coders seem want to take advantage of observed behaviour, rather than following the tech docs. Looking back at the screenshots I have posted, is a great way to see how much I have learnt (seriously, this has to be one of the best ways to learn how this stuff works). -Edit- One idea I have toyed with is using "byteplane" buffer... so the blitter copies in the pixel data, and stores each bit in as a byte in the internal buffer (obviously this requires 8 times as much memory), operates on the byte buffer, then then once the blitter operation is completed copies the data back to the original format... Attached Thumbnails Last edited by bloodline; 01 March 2018 at 15:52.

11 February 2018, 12:02	#31
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	I appear to have a working line mode implementation now. I'm guessing the missing vertical and horizontal areas are to be filled by the area copy mode. But my area copy mode is totally broken... I assumed that area mode would be the easy part... time for (another) rewrite. Attached Thumbnails

11 February 2018, 13:59	#32
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	Area mode rewrite... almost there?! Attached Thumbnails

05 February 2018, 14:12	#21
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,504	If I remember correctly, KS 1.x boot screen assumes blitter undocumented feature: linedraw mode uses C modulo register for both C and D channels. D modulo is ignored. (There are also other linedraw undocumented features but they are not needed to get KS code working)

05 February 2018, 20:08	#24
nogginthenog Amigan Join Date: Feb 2012 Location: London Posts: 1,309	Nice Reminds me of the early UAE days when Bernd Schmidt posted similar screenshots (possibly to USENET?).

10 February 2018, 01:28	#27
Sinphaltimus Registered User Join Date: Aug 2016 Location: Cresco, PA, USA Age: 53 Posts: 1,126	Sweet. Congrats!

11 February 2018, 14:17	#33
bloodline Registered User Join Date: Jan 2017 Location: London, UK Posts: 433	Something still not right... but this is enough for today -Edit- The attached executable, is compiled for MacOS Sierra, and requires libSDL 2.0+ installed. Run from command line: zorro <path to rom image> It will spew out quite a bit of debugging info... enjoy. Attached Thumbnails Last edited by bloodline; 01 March 2018 at 15:52.

11 February 2018, 14:31	#34
wodan Registered User Join Date: Feb 2018 Location: Kidderminster Posts: 16	Could be an off by one error (as in one word to the side), looks like you're close!

11 February 2018, 22:11	#38
rare_j Zone Friend Join Date: Apr 2005 Location: London Posts: 1,176	I haven't made suggestions but I have followed. I hope you continue to build on this as long as you're having fun

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