Snapperazzi, another weird bootblock issue!!

[BarryB]

So Snapperazzi, another Alternative Software game, has a weird bootblock similar to the one I found on Postman Pat III (which ross examined) and stops an ADF or self made IPF of Disk 1 from loading in WinUAE, it appears to be just plain ADOS!

Loading the official IPF it also seems to need 1mb of Chip as any config with 512kb chip + 512kb fast won't let it load in WinUAE.

Creating an ADF and installing a standard 1.3 bootblock will also let it load if you use a 1mb+ chip config in WinUAE!

So what's the deal with this bootblock, is it the same issue as ross found, and why does it appear to need 1mb chip?

My dump is identical to the official IPF HERE!

[ross]

Yes, the same useless protection.

If the game doesn't check the protection on track 0 later during the main code, that bootblock doesn't make any sense.

And yes, the game require 1MB chip RAM.

[BarryB]

Originally Posted by ross

Yes, the same useless protection.

If the game doesn't check the protection on track 0 later during the main code, that bootblock doesn't make any sense.

And yes, the game require 1MB chip RAM.

Thanks ross

I guess the bootblock was just to stop casual copying then as Abaddon did the WHDLoad installer and he doesn't mention any 'protection' in the readme. The 1mb chip was probably because the A500+, A600 & A1200 were the newest Amigas in 1993 when the game was released, although the game does not seem to load on an A1200!

[ross]

Originally Posted by BarryB

... although the game does not seem to load on an A1200!

hmm, this is strange.. do you mean in a real Amiga 1200?
I tried with a Quickstart A1200 (base or + 4MB fast RAM) and it load without issues.
Perhaps, if you used WinUAE, was it an old version? Or with some peculiar configuration?

[BarryB]

Originally Posted by ross

hmm, this is strange.. do you mean in a real Amiga 1200?
I tried with a Quickstart A1200 (base or + 4MB fast RAM) and it load without issues.
Perhaps, if you used WinUAE, was it an old version? Or with some peculiar configuration?

Just the basic A1200 config without fast ram in the latest WinUAE, just sticks on the bootblock. Just tried an older beta on another system and does load, will have to check my WinUAE setup!

[BarryB]

Abaddon has looked at this also and has this interesting observation:

So the boot block code reads track 0.1 without a sync and expects to find the first sync (shifted) of the standard ados data at an offset between 0x1a8 and 0x1e0

So this is why ADF's or self generated IPF's do not work as track 0.1 is not in the correct position on the disk. Abaddon will be supporting this in the next update to disk-utilities!

As for not loading on an A1200 config, seems it's the 4.10 builds of WinUAE as it loads in 4.9.1

Actually, it's because 4.10.x now needs Cycle-exact (Full) ticking in Chipset for some reason before it will load?