Aros on ACA500+ with ACA1221LC

JanBlomqvist · Feb 2nd 2021

Hi, I would like to try out AROS on my Amiga 500 with ACA500+ and the ACA1221lc. I have looked for how to do such a thing on the internet but I can't find any instruction on how to do that, can someone direct me in a good way to do this. Om Aminet I've found a bootdisk and the rom, but that rom is split in two so I don't understand howto solve that, the once on Amiga Forever seams to be split too. I wonder perhaps it's possible to join the two into one and insert it in a 1M slot in the ACA500+ but how do I do that in that case.

Then what distribution would work on a m68k machine like this?

Please someone?

/Jan Blomqvist

Jens · Feb 2nd 2021

Never looked at AROS before, but judging from the file names, the "ext" file and the "-rom" file (which are both exactly 512k) need to be joined into a single 1MB file. You need to know that Kickstart is split into two physical 512k chunks on the Amiga, one located at $f8.0000 and the other located at $e0.0000. Back when I made the first ACA1230 accelerator, we also introduced 1MByte Kickstart, which was Commodore's plan all along. For simplicity, we've put it all into a single 1MByte file and have ACAtune figure it out for the user.

The AROS people obviously took a more technical approach and split the files.

Try this command line:

Code

join aros-amiga-m68k-ext.bin aros-amiga-m68k-rom.bin AS aros-amiga-m68k-1MB.bin

This will generate a single 1MB file that the ACA500plus tools should eat.

JanBlomqvist · Feb 2nd 2021

Hi, thanks for the tip, though I couldn't get it to work, I tried both as you typed it and the other way around, but it only saw 512K roms in the ACA500+ after flashing them (I flashed it on the slot 5 but as you wrote it it ended up at slot 7 when I switched them around at slot 5) and when I inserted the bootdisk and tried to boot, I was directed into HRMon directly before even the drive started. Any idea of how to solve it? probably just some bits between these two chunk of ROM and it'll work.

/Jan

Jens · Feb 3rd 2021

Once again, I never tried AROS myself and this is going beyond regular product support.

Please check if the JOIN command has worked properly - do a LIST in the directory you've executed it and see if the size is really 1048576 bytes.

JanBlomqvist · Feb 3rd 2021

Hi again Jens, thanks for your advice, yes, the Join worked right, both the files that I joined

Code

join aros-amiga-m68k-ext.bin aros-amiga-m68k-rom.bin AS aros-amiga-m68k-1MB.bin
and
join aros-amiga-m68k-rom.bin aros-amiga-m68k-ext.bin AS aros-amiga-m68k-1MB

Both worked with out any problems, but the try that had the "aros-amiga-m68k-rom.bin" last (as you suggested) landed at slot 7 but when it was first it landed at slot 5 as expected (the "ext" would in my mind be last and the "rom" should be where the ACA500+ would in my mind look for the beginning in that file. The ACA however didn't notice the last part probably because some kind of "end bit/byte" in the first file or something like it.

Jens · Feb 4th 2021

Quote from JanBlomqvist

(the "ext" would in my mind be last

Since Kickstart has always been at the end of memory space (first $fc.0000 for 256k-Kicks, then $f8.0000 for 512k-Kicks) and the $e0 area is considered "extended", I'd put the extended ROM first in a 1MB file. Not sure if the AROS guys are using the same naming. Isn't there anyone from the AROS team available in some other forum or chat?

In any case, slots 4 to 7 must be empty before you flash them. I have a hard time believing that you crammed a 1M flash to slot 5, as that would only give you 768k of space (every slot is 256k).

Quote from JanBlomqvist

The ACA however didn't notice the last part probably because some kind of "end bit/byte" in the first file or something like it.

I've had the idea for a "plausibility check" some time ago, but I'm not sure if Toni has implemented that: I wanted the flash tools to check if the reset vector points to a valid address within the Kickstart that you're about to flash. This would not be an "end bit or byte", but a simple verification of the contents of the vector. Looks like this worked, and you were pointed to the fact that what you'Re about to flash will result in a non-working config.

JanBlomqvist · Feb 4th 2021

Hi again, only 1 and 5 can hold 1024 KB roms on the ACA500+ and it worked both to Join the files and to flash them, however noone of the two tested roms worked.

Because the behaviour of the burned roms appeared first in the slot 7 and then in slot 5 i guess the content of the roms shows where the first is and that it ends after the first 512KB I believe the jioned rom needs to be edited somehow to get the resr of the 512Kb to work.

Jens · Feb 4th 2021

Quote from JanBlomqvist

Hi again, only 1 and 5 can hold 1024 KB roms on the ACA500+ and it worked both to Join the files and to flash them, however noone of the two tested roms worked.

My mistake - I normally start counting at 0, while the slot numbering starts at 1.

JanBlomqvist · Feb 4th 2021

I thought I should try to boot the AROS boot disk that bootstraps the two roms in the RAM from my ACA 500+ but that actually also crashes, perhaps the problems is elsewhere?

Jens · Feb 4th 2021

Again, I never tried AROS, so I can only point you to a "requirements" section of the documentation and find out if your config fulfills that.

Also, please note that the ACA1221lc has a very high amount of memory for a CPU with only 16MBytes of address space. There may be a bug in AROS that uses more memory or assumes a completely different config, given that the CPU and Gayle identificatoin of the complete system may trigger A1200/AGA routines to run.