Dumping the A1000 bootstrap ROM

[andreas]

Is this possible somehow?

Latest (available) TOSEC Kickstart images dat lists the ROM as follows:

A1000 ROM Bootstrap (1985)(Commodore)[u]

where [u] = underdump.

Which (probably) means: not complete, redump appreciated.
I do have such an A1000 machine to dump the bootstrap ROM, but I don't have a clue yet how to get that complete (!) ROM data off the hardware (i. e. the chips named C252179-01 and C252180-01)

Any ideas, tools to use, anything?
And BTW: what is the expected size of an A1000 bootstrap ROM? Not 8K?

[Toni Wilen]

Using EPROM-burner is the best way to dump them. They only contain just under 8kb of data and I don't really see any point of using bigger (more expensive) roms just for bootstrapping. (but we are talking about Commodore here..)

I hope someone can confirm the real size of chips..

[Computolio]

There's not a chance in hell of somehow squeezing a Kickstart ROM into the bootROM sockets, is there? What would happen if someone replaced those ROMs with a 256K Kickstart spread across four 27C1001 EPROMs (two in the existing sockets and two in the unused sockets)?

[derSammler]

And BTW: what is the expected size of an A1000 bootstrap ROM? Not 8K?

Only 8 KB of data but on a 64 KB rom.


@Toni: From the changelog of WinUAE 0.8.22r1b1:

64kb A1000 boot rom supported (A1000 boot rom size is really 64kb even if only first 8kb is used..)

You should remember your own statements.

[andreas]

@Windowskiller, it's a fact that we've really got drowned in changelogs lastly, so no wonder this escaped me.
Thanks for the reminder.

@Toni

Using EPROM-burner is the best way to dump them. They only contain just under 8kb of data and I don't really see any point of using bigger (more expensive) roms just for bootstrapping.

Ugh...in my juvenile carelessness, I have rather been thinking of a tool on Amiga side that could make a dump of the ROM into a file. Any Amiga coder should be able to write this in about half an hour. (?)
I can't code on Amiga side, though (save from AmigaBASIC stuff!)

[derSammler]

Any Amiga coder should be able to write this in about half an hour. (?)

Yes, it's really simple:

#include <stdio.h>
int main(void)
{
  fwrite((char *)0xF40000,sizeof(char),0x10000,stdout);
  return 0;
}

However, I don't now the exact address of the boot rom, 0xF40000 is just a guess and probably wrong.

[Toni Wilen]

Originally Posted by WindowsKiller

Yes, it's really simple:

No, it isn't simple. A1000 Boot ROM is completely hidden (located "under" normal KS ROM space) after KS disk has been loaded..

68000 RESET-instruction maps the boot ROM (and enables write-access to KS RAM) but unfortunately it also unmaps all chip and fast ram which makes dumping quite hard

I think there is solution but I need to do some testing first..

[derSammler]

A1000 Boot ROM is completely hidden (located "under" normal KS ROM space) after KS disk has been loaded..

Oops... I didn't knew that.

[Jope]

Soooo, what happened to the ROMs I dumped for you way back when from my original A1000 bootstrap chips?

I can do a redump if they were knackered somehow - I still have the A1000.

Or is this thread just about people wanting to dump the kickstart roms without pulling them out?

[andreas]

no, wanting to get a *FULL* dump for tosec.
The one we have is correctly (!) renamed [u] for underdump, because it contains valid data, but apparently not the full contents of the hardware chip.

[Toni Wilen]

Here is simple and stupid A1000 boot rom dumper.. (source included)

instructions:

- run executable
- program forces mapping of boot rom and copies addresses between $f80000 to $fc0000 to chip ram at $38000 (boot rom is located at $f80000 to $f90000, if it really is 64kb..)
- wait until colors flash
- reset the amiga (there is no way to return back to amigados without reseting)
- boot with minimal bootable disk containing utility that can be used to save memory to disk
- save memory from $38000 to $48000 to disk

[Jope]

Originally Posted by andreas

no, wanting to get a *FULL* dump for tosec. :)
The one we have is correctly (!) renamed [u] for underdump, because it contains valid data, but apparently not the full contents of the hardware chip.

Ok.. I did dump both chips for Toni a few years ago (the bootstrap ROM is divided into two 8bit chips), but I guess I only dumped the first half of them, or so (the rest was probably just full of FF)

Oh well, hope someone manages a full dump, I can't be bothered to fetch my A1000 remains from the cellar. :-)

[andreas]

2x 8bit??!

Then I hope the size of my current ROM will match both of them!
It's now 64K in size.
(And yes, you're right. Beyond the 8K, there are only $FFs )

[Mangar]

While searching through a french pack of a french version of AIAB I managed to find a kickstart 1.0 rom. Its 256k and looks to be the complete real deal.

I'll send it to the zone for you to check out.

[fiath]

Originally Posted by andreas

2x 8bit??!

68000-based systems generally use two ROM with interleaved bytes. The odd bytes are on one ROM, and the even bytes on the other. It is just a side effect of how the addressing works. You may notice that MAME keeps these types of ROM's in two seperate files (not all used to be like this, but they were changing them to reflect the real chips, so probably all are now), since it is a documentation project of the hardware, and also because the MAME ROM sets are intended to (and are used to) allow fixing of real arcade systems.

Since (all?) Amiga kickstart's are carried on two ROM's, strictly speaking, these should really be two files too. I guess it is just not quite as practical from an emulation point of view.

[derSammler]

Since (all?) Amiga kickstart's are carried on two ROM's

Only Kickstarts for A1200, 4000 and 3000 are on two ROMs. The Kickstarts for A500, 600, 2000 are all on one ROM.

[Jope]

Most likely the A1000 bootstrap was divided into two 8-bit wide ROMs because of price reasons..

I can imagine 16-bit wide chips were quite a bit more expensive back in 1985.

[Jope]

Originally Posted by andreas

(And yes, you're right. Beyond the 8K, there are only $FFs :))

Thought as much.

I remember scrolling through the contents of the chips and then deciding to save only the part with the actual data..

Toni, did you send my dumps to tosec, or where did they get that?

[Toni Wilen]

Originally Posted by Jope

Thought as much.

I remember scrolling through the contents of the chips and then deciding to save only the part with the actual data..

Toni, did you send my dumps to tosec, or where did they get that?

I don't remember much anymore but I am quite sure I only sent it to Cloanto for inclusion in Amiga Forever. There was also another guy who dumped the A1000 ROMs too but I don't have his name or email address anymore.. I only remember that ROM contents were identical.

Toni,

I dumped mine as well. I also coordinated the dumps of about 50 others, both PAL and NTSC, single and double-board, and they are _all_ identical in every respect. And yes, only 8K of the ROM is really used, though I was the one that prodded you long ago into supporting the full 64K dump. <G>

If someone wants me to e-mail them directly with the latest version of the bootable A1000 Boot ROM dump tool, give me an address and I'll do so. Even better if someone could put it in the Zone ('cuz I don't know how and can't be bothered .

Rodney