Re: [hatari-devel] Starglider 1 doesn't work anymore with Hatari

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

On 08/11/2012 11:46, Nicolas Pomarède wrote:
> Hello
>
> I gave a quick look yesterday, and the game tries to read sector 247 on
> track 79, this is not a gemdos issue.
> I think the protection test is still made, except the result is
> discarded in the end, so the game starts anyway, even on a standard floppy.
>
> Now I need to see what is wrong when the fdc code deals with unknown
> sector (hatari 1.4 was completly wrong on this part, but in this
> specific case, it worked  by luck)
>
> Nicolas

Looking at the code from this game, it does a read sector on track 79 
sector 247 then check for bit 4 of fdc's status register to be 0, which 
means no error was encountered and sector was correctly read.

But ST/MSA disk image can't store sector number 247, they can't even 
store any sector number, they just assume sector 1..n are present for 
each track.

So, sorry, but this disk is protected ; a very simple protection that 
any ST copier would copy, but still you would need a .stx (pasti) or 
..ipf file to store track 79.

No error in the FDC code, Hatari was just incomplete on this part 
(running this .st disk image using Steem with or without pasti library 
enabled will also fail in both cases)


Nicolas