Velvet Bootblock

[banderson38911]

Hello,

I've been messing around with/documenting the features of the Kickstart 0.4 ROM in WinUAE and was wondering how to create or modify a bootblock for an ADF so it will run (virtually) on an A1000 "Velvet" system.

Thanks,
-Bernard Anderson

[Tomislav]

Does 0.4 have trackdisk.device? I'm thinking that for earlier betas maybe they used some 720K sized format?!?!
Sadly, 0.4 is not included in AmigaForever, although some people say that Cloanto have it.

[Toni Wilen]

I haven't checked the format but afaik it is something very different than usual Amiga MFM format. Standard ADF won't work, it needs to be extended ADF.

[mark_k]

I think it uses standard trackdisk format.

I made a bootable ADF for it, see this post.

Also a ROM-dumping ADF, see this other post.

Neither was tested on real hardware though.

[banderson38911]

Originally Posted by Tomislav

Does 0.4 have trackdisk.device?

Yes it does. Albeit with fewer commands.

[banderson38911]

Originally Posted by mark_k

I think it uses standard trackdisk format.

I made a bootable ADF for it, see this post.

Also a ROM-dumping ADF, see this other post.

Neither was tested on real hardware though.

I downloaded the ADFs and unfortunately they don't seem to work, they boot to the usual black screen with green garbage. The ROM is 128K and starts at $FE0000.

[banderson38911]

Originally Posted by Toni Wilen

I haven't checked the format but afaik it is something very different than usual Amiga MFM format. Standard ADF won't work, it needs to be extended ADF.

Hello Toni. I think I found the bootblock checksum in Exec. The routine in question is at $FE0400-FE041E in the Kickstart 0.4 ROM.

[mark_k]

Originally Posted by banderson38911

I downloaded the ADFs and unfortunately they don't seem to work, they boot to the usual black screen with green garbage. The ROM is 128K and starts at $FE0000.

I could have sworn I tested in WinUAE (using whichever version was current at the time). Could something have changed with WinUAE's velvet emulation since then???

[Toni Wilen]

Works for me. It runs this loop:

00010000 41f9 00df f180           LEA.L $00dff180,A0
00010006 43e8 fe86                LEA.L (A0,-$017a) == $00dff006,A1
0001000A 317c 4000 ff1a           MOVE.W #$4000,(A0,-$00e6) == $00dff09a
00010010 3091                     MOVE.W (A1),(A0)
00010012 3091                     MOVE.W (A1),(A0)
00010014 3091                     MOVE.W (A1),(A0)
00010016 3091                     MOVE.W (A1),(A0)
00010018 60f6                     BT .B #$f6 == $00010010

[mark_k]

Originally Posted by banderson38911

I downloaded the ADFs and unfortunately they don't seem to work, they boot to the usual black screen with green garbage. The ROM is 128K and starts at $FE0000.

Is the WinUAE config you're using set to emulate the Velvet hardware? Just loading the Velvet Kickstart on an A500 (or other retail Amiga) config wouldn't work.

[banderson38911]

Originally Posted by mark_k

Is the WinUAE config you're using set to emulate the Velvet hardware? Just loading the Velvet Kickstart on an A500 (or other retail Amiga) config wouldn't work.

Yes. I have configured WinUAE for the Velvet hardware and ROM in versions 4.4.0 and 3.1.0.

Which one are you using?

[Toni Wilen]

Did you configure Velvet using Quickstart? It is too easy to get manual config wrong.

Also add -log -serlog to command line, you should see some Velvet ROM debugging messages in log window.

[banderson38911]

Originally Posted by Toni Wilen

Did you configure Velvet using Quickstart? It is too easy to get manual config wrong.

Also add -log -serlog to command line, you should see some Velvet ROM debugging messages in log window.

No I didn't. Will try that now.

[banderson38911]

Originally Posted by banderson38911

No I didn't. Will try that now.

Alright. Configured Velvet in Quickstart and rescanned the ROMS. The ADF to dump the Velvet ROM is doing something. Now after displaying the "green garbage" the background changes to yellow, flashing white, then all lime green.

In other words, I think it works!