Kickstart 40.63

[polluks]

My image is not recognised. Is there any option to bypass the check?

[dirkwhoffmann]

There are multiple 40.63 images around. vAmiga recognizes the following:

Kickstart v3.1 rev 40.63 (1993)(Commodore)(A500-A600-A2000)[!].rom

It's the one with this header signature: 0x11, 0x14, 0x4E, 0xF9, 0x00, 0xF8, 0x00

However, it doesn't seem to work any more. It's broken in v2.1b4:

It works in v2.01. Needs investigation...

[dirkwhoffmann]

Update: There are two other variants I know about:

Kickstart v3.1 rev 40.63 (1993)(Commodore)(A500-A600-A2000).rom Kickstart v3.1 rev 40.63 (1993)(Commodore)(A500-A600-A2000)[b].rom

The first one has CRC 88136ca9 and seems to be broken. The second one has an unusual file size (524293 instead of 524288) and is rejected because of this reason.

[polluks]

My ROM MD5 (Kickstart v3.1 rev 40.63 (1993)(Commodore)(A500-A600-A2000).rom) = 0b839c665635a249c5736118c68a69a7 00000000: 1116 4ef9 0020 00d2 0000 ffff 0028 0044 ..N.. .......(.D

[dirkwhoffmann]

MD5 = 0b839c665635a249c5736118c68a69a7

Yes, that's the one which I suppose is broken. Have out tried this Rom in UAE? In my UAE installation, I get a green screen of death. Of course there is always the chance that I was using an incompatible hardware configuration.

[dirkwhoffmann]

BTW, Cloanto has a nice page summarizing various Roms. Your Rom is listed as:

V. 3.1 | Dec 1993 | 40.068 | ReCode |   | 524288 | 200000 | 68000 | A600 | Developer | Confirmed as hack of 8ECED804 by Rodney Hester

Clicking on 'Details' reveals:

The following bytes were changed from the original ROM (checksum AE733766):
0000008C-0000008D: Changed spaces after "3.1 ROM" to NULLs (why?)
00000511-00000513: Changed to 0x27FF0A (jump to cache clear code?)
000035DC-000035DD: Changed to 0x4A2E to disable beta alert
         0004D765: Changed to 0xEB to activate NoClick
0007F639-0007F663: Changed Workbench title to "OS 3.1   %lD graphics mem  %lD other mem   "
0007FF00-0007FF4B: Inserted the following block of code (clear caches?):

4C DF 41 01 4E F9 00 20 0A 90 48 E7 80 82 2C 78
00 04 08 2E 00 00 01 29 67 E6 20 6F 00 0E 30 10
02 40 FF C0 0C 40 40 C0 66 D6 00 10 00 02 08 2E
00 01 01 29 67 10 4E 7B 88 02 4E 7A 00 02 08 C0
00 02 4E 7B 00 02 4C DF 41 01 4E 73

0007FFE8-0007FFEB: Changed ROM checksum to DB4247E0

Interestingly, the Cloanto page also provides some screenshots for this Rom which means that it has to work somehow. The next step should be to find a working hardware configuration in UAE.

[mras0]

Note that it's a ReKick (ReCode) image meant to be loaded into fast ram. ($1116 identifier and $002000d2 starting address)

[dirkwhoffmann]

Note that it's a ReKick

Interesting (never heard about that before).

I've a done a quick experiment and added a Rom mirror where the Rom is supposed to reside:

Kickstart starts executing, but ends up in a green screen (which means the memory test fails).

I still need to check why it fails...

[mras0]

Looks like it expects OVL to be cleared in ciaapra (i.e. memory visible at $0). First thing it does is write exceptions vectors and check if they were written correctly. I don't know if it makes other assumptions about the system state that are not normally true after reset.

[dirkwhoffmann]

Looks like it expects OVL to be cleared in ciaapra

Yes, I have stepped through the first instructions and noticed this, too. I guess the Rom relies on a couple of initializations that would be carried out by the standard Rom in a normal setup (Original Rom at $F80000 and ReKick at $200000).

[dirkwhoffmann]

I think it's best to let vAmiga recognize ReKick images and inform the user that they won't work the same way as ordinary Roms:

[dirkwhoffmann]

723 is a follow-up to this issue (ECS Denise graphics bug).